Use maintenance_io_concurrency where needed [skip ci]

Updated comment [skip ci]
Fixed compiler warning [skip ci]
2026-07-22 03:57:34 +08:00 · 2025-07-12 09:12:00 -07:00 · 2025-07-12 09:10:43 -07:00 · 2025-07-12 08:58:07 -07:00 · 2025-07-11 18:45:54 -07:00 · 2025-07-11 18:38:44 -07:00
39 changed files with 309 additions and 888 deletions
--- a/.dockerignore
+++ b/.dockerignore
@@ -0,0 +1,15 @@
+/.git/
+/dist/
+/log/
+/results/
+/tmp_check/
+/sql/vector--?.?.?.sql
+regression.*
+*.o
+*.so
+*.bc
+*.dll
+*.dylib
+*.obj
+*.lib
+*.exp
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -8,8 +8,6 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - postgres: 19
-            os: ubuntu-24.04
          - postgres: 18
            os: ubuntu-24.04
          - postgres: 17
@@ -23,14 +21,14 @@ jobs:
          - postgres: 13
            os: ubuntu-22.04
    steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v4
      - uses: ankane/setup-postgres@v1
        with:
          postgres-version: ${{ matrix.postgres }}
          dev-files: true
      - run: make
        env:
-          PG_CFLAGS: -DUSE_ASSERT_CHECKING -Wall -Wextra -Werror -Wno-unused-parameter -Wno-sign-compare ${{ matrix.postgres >= 18 && '-Wno-missing-field-initializers' || '' }}
+          PG_CFLAGS: ${{ matrix.postgres == 18 && '-Wno-missing-field-initializers' || '' }} -DUSE_ASSERT_CHECKING -Wall -Wextra -Werror -Wno-unused-parameter -Wno-sign-compare
      - run: |
          export PG_CONFIG=`which pg_config`
          sudo --preserve-env=PG_CONFIG make install
@@ -48,18 +46,18 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - postgres: 18
-            os: macos-26
+          - postgres: 17
+            os: macos-15
          - postgres: 14
-            os: macos-15-intel
+            os: macos-13
    steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v4
      - uses: ankane/setup-postgres@v1
        with:
          postgres-version: ${{ matrix.postgres }}
      - run: make
        env:
-          PG_CFLAGS: -DUSE_ASSERT_CHECKING -Wall -Wextra -Werror -Wno-unused-parameter -Wno-unknown-warning-option ${{ matrix.postgres >= 18 && '-Wno-missing-field-initializers' || '' }}
+          PG_CFLAGS: -DUSE_ASSERT_CHECKING -Wall -Wextra -Werror -Wno-unused-parameter -Wno-unknown-warning-option
      - run: make install
      - run: make installcheck
      - if: ${{ failure() }}
@@ -72,35 +70,27 @@ jobs:
          tar xf $TAG.tar.gz
          mv postgres-$TAG postgres
        env:
-          TAG: ${{ matrix.postgres == 18 && 'REL_18_2' || 'REL_14_21' }}
+          TAG: ${{ matrix.postgres == 17 && 'REL_17_2' || 'REL_14_15' }}
      - run: make prove_installcheck PROVE_FLAGS="-I ./postgres/src/test/perl -I ./test/perl"
        env:
          PERL5LIB: /Users/runner/perl5/lib/perl5
      - run: make clean && $(brew --prefix llvm@$LLVM_VERSION)/bin/scan-build --status-bugs make
        env:
-          LLVM_VERSION: ${{ matrix.os == 'macos-26' && 20 || 18 }}
+          LLVM_VERSION: ${{ matrix.os == 'macos-15' && 18 || 15 }}
          PG_CFLAGS: -DUSE_ASSERT_CHECKING
  windows:
-    runs-on: ${{ matrix.os }}
+    runs-on: windows-latest
    if: ${{ !startsWith(github.ref_name, 'mac') }}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - postgres: 17
-            os: windows-2025
-          - postgres: 14
-            os: windows-2022
    steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v4
      - uses: ankane/setup-postgres@v1
        with:
-          postgres-version: ${{ matrix.postgres }}
+          postgres-version: 14
      - run: |
-          call "C:\Program Files\Microsoft Visual Studio\${{ matrix.os == 'windows-2025' && 18 || 2022 }}\Enterprise\VC\Auxiliary\Build\vcvars64.bat" && ^
+          call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvars64.bat" && ^
          nmake /NOLOGO /F Makefile.win && ^
          nmake /NOLOGO /F Makefile.win install && ^
-          nmake /NOLOGO /F Makefile.win installcheck ${{ matrix.postgres != 17 && 'PG_REGRESS=$(PGROOT)\bin\pg_regress' || '' }} && ^
+          nmake /NOLOGO /F Makefile.win installcheck && ^
          nmake /NOLOGO /F Makefile.win clean && ^
          nmake /NOLOGO /F Makefile.win uninstall
        shell: cmd
@@ -133,10 +123,10 @@ jobs:
    if: ${{ !startsWith(github.ref_name, 'mac') && !startsWith(github.ref_name, 'windows') }}
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@v4
      - uses: ankane/setup-postgres-valgrind@v1
        with:
-          postgres-version: 18
+          postgres-version: 17
          check-ub: yes
      - run: make OPTFLAGS=""
      - run: sudo --preserve-env=PG_CONFIG make install
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,18 +1,6 @@
-## 0.8.3 (unreleased)
+## 0.8.1 (unreleased)

- Fixed possible index corruption with HNSW vacuuming
- Fixed performance regression with Hamming distance and Jaccard distance with Postgres 18
-
-## 0.8.2 (2026-02-25)
-
- Fixed buffer overflow with parallel HNSW index build - [more info](https://github.com/pgvector/pgvector/issues/959)
- Improved `install` target on Windows
- Fixed `Index Searches` in `EXPLAIN` output for Postgres 18
-
-## 0.8.1 (2025-09-04)
-
- Added support for Postgres 18 rc1
- Improved performance of `binary_quantize` function
+- Improved performance of HNSW index scans for Postgres 17

 ## 0.8.0 (2024-10-30)

--- a/7
+++ b/7
@@ -1,11 +1,8 @@
-# syntax=docker/dockerfile:1
-
 ARG PG_MAJOR=17
-ARG DEBIAN_CODENAME=bookworm
-FROM postgres:$PG_MAJOR-$DEBIAN_CODENAME
+FROM postgres:$PG_MAJOR
 ARG PG_MAJOR

-ADD https://github.com/pgvector/pgvector.git#v0.8.2 /tmp/pgvector
+COPY . /tmp/pgvector

 RUN apt-get update && \
 		apt-mark hold locales && \
--- a/2
+++ b/2
@@ -1,4 +1,4 @@
-Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
+Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group

 Portions Copyright (c) 1994, The Regents of the University of California

--- a/META.json
+++ b/META.json
@@ -2,7 +2,7 @@
 	"name": "vector",
 	"abstract": "Open-source vector similarity search for Postgres",
 	"description": "Supports L2 distance, inner product, and cosine distance",
-	"version": "0.8.2",
+	"version": "0.8.0",
 	"maintainer": [
 		"Andrew Kane <andrew@ankane.org>"
 	],
@@ -20,7 +20,7 @@
 		"vector": {
 			"file": "sql/vector.sql",
 			"docfile": "README.md",
-			"version": "0.8.2",
+			"version": "0.8.0",
 			"abstract": "Open-source vector similarity search for Postgres"
 		}
 	},
--- a/14
+++ b/14
@@ -1,5 +1,5 @@
 EXTENSION = vector
-EXTVERSION = 0.8.2
+EXTVERSION = 0.8.0

 MODULE_big = vector
 DATA = $(wildcard sql/*--*--*.sql)
@@ -27,11 +27,6 @@ ifneq ($(filter ppc64%, $(shell uname -m)), )
 	OPTFLAGS =
 endif

-# RISC-V64 doesn't support -march=native
-ifeq ($(shell uname -m), riscv64)
-	OPTFLAGS =
-endif
-
 # For auto-vectorization:
 # - GCC (needs -ftree-vectorize OR -O3) - https://gcc.gnu.org/projects/tree-ssa/vectorization.html
 # - Clang (could use pragma instead) - https://llvm.org/docs/Vectorizers.html
@@ -81,9 +76,4 @@ docker:
 .PHONY: docker-release

 docker-release:
-	docker buildx build --push --pull --no-cache --platform linux/amd64,linux/arm64 --build-arg PG_MAJOR=$(PG_MAJOR) --build-arg DEBIAN_CODENAME=bookworm -t pgvector/pgvector:pg$(PG_MAJOR) -t pgvector/pgvector:pg$(PG_MAJOR)-bookworm -t pgvector/pgvector:$(EXTVERSION)-pg$(PG_MAJOR) -t pgvector/pgvector:$(EXTVERSION)-pg$(PG_MAJOR)-bookworm .
-
-.PHONY: docker-release-trixie
-
-docker-release-trixie:
-	docker buildx build --push --pull --no-cache --platform linux/amd64,linux/arm64 --build-arg PG_MAJOR=$(PG_MAJOR) --build-arg DEBIAN_CODENAME=trixie -t pgvector/pgvector:pg$(PG_MAJOR)-trixie -t pgvector/pgvector:$(EXTVERSION)-pg$(PG_MAJOR)-trixie .
+	docker buildx build --push --pull --no-cache --platform linux/amd64,linux/arm64 --build-arg PG_MAJOR=$(PG_MAJOR) -t pgvector/pgvector:pg$(PG_MAJOR) -t pgvector/pgvector:$(EXTVERSION)-pg$(PG_MAJOR) .
--- a/Makefile.win
+++ b/Makefile.win
@@ -1,5 +1,5 @@
 EXTENSION = vector
-EXTVERSION = 0.8.2
+EXTVERSION = 0.8.0

 DATA_built = sql\$(EXTENSION)--$(EXTVERSION).sql
 OBJS = src\bitutils.obj src\bitvec.obj src\halfutils.obj src\halfvec.obj src\hnsw.obj src\hnswbuild.obj src\hnswinsert.obj src\hnswscan.obj src\hnswutils.obj src\hnswvacuum.obj src\ivfbuild.obj src\ivfflat.obj src\ivfinsert.obj src\ivfkmeans.obj src\ivfscan.obj src\ivfutils.obj src\ivfvacuum.obj src\sparsevec.obj src\vector.obj
@@ -31,9 +31,6 @@ LIBDIR = $(PGROOT)\lib
 PKGLIBDIR = $(PGROOT)\lib
 SHAREDIR = $(PGROOT)\share

-# Use $(PGROOT)\bin\pg_regress for Postgres < 17
-PG_REGRESS = $(LIBDIR)\pgxs\src\test\regress\pg_regress
-
 CFLAGS = /nologo /I"$(INCLUDEDIR_SERVER)\port\win32_msvc" /I"$(INCLUDEDIR_SERVER)\port\win32" /I"$(INCLUDEDIR_SERVER)" /I"$(INCLUDEDIR)"

 CFLAGS = $(CFLAGS) $(PG_CFLAGS)
@@ -57,11 +54,11 @@ install: all
 	copy $(SHLIB) "$(PKGLIBDIR)"
 	copy $(EXTENSION).control "$(SHAREDIR)\extension"
 	copy sql\$(EXTENSION)--*.sql "$(SHAREDIR)\extension"
-	if not exist "$(INCLUDEDIR_SERVER)\extension\$(EXTENSION)" mkdir "$(INCLUDEDIR_SERVER)\extension\$(EXTENSION)"
+	mkdir "$(INCLUDEDIR_SERVER)\extension\$(EXTENSION)"
 	for %f in ($(HEADERS)) do copy %f "$(INCLUDEDIR_SERVER)\extension\$(EXTENSION)"

 installcheck:
-	"$(PG_REGRESS)" --bindir="$(BINDIR)" $(REGRESS_OPTS) $(REGRESS)
+	"$(BINDIR)\pg_regress" --bindir="$(BINDIR)" $(REGRESS_OPTS) $(REGRESS)

 uninstall:
 	del /f "$(PKGLIBDIR)\$(SHLIB)"
--- a/README.md
+++ b/README.md
@@ -11,8 +11,6 @@ Store your vectors with the rest of your data. Supports:

 Plus [ACID](https://en.wikipedia.org/wiki/ACID) compliance, point-in-time recovery, JOINs, and all of the other [great features](https://www.postgresql.org/about/) of Postgres

-Have a lot of vectors? Use [quantization](#scaling) to scale
-
 [![Build Status](https://github.com/pgvector/pgvector/actions/workflows/build.yml/badge.svg)](https://github.com/pgvector/pgvector/actions)

 ## Installation
@@ -23,7 +21,7 @@ Compile and install the extension (supports Postgres 13+)

 ```sh
 cd /tmp
-git clone --branch v0.8.2 https://github.com/pgvector/pgvector.git
+git clone --branch v0.8.0 https://github.com/pgvector/pgvector.git
 cd pgvector
 make
 make install # may need sudo
@@ -31,16 +29,16 @@ make install # may need sudo

 See the [installation notes](#installation-notes---linux-and-mac) if you run into issues

-You can also install it with [Docker](#docker), [Homebrew](#homebrew), [PGXN](#pgxn), [APT](#apt), [Yum](#yum), [pkg](#pkg), [APK](#apk), or [conda-forge](#conda-forge), and it comes preinstalled with [Postgres.app](#postgresapp) and many [hosted providers](#hosted-postgres). There are also instructions for [GitHub Actions](https://github.com/pgvector/setup-pgvector).
+You can also install it with [Docker](#docker), [Homebrew](#homebrew), [PGXN](#pgxn), [APT](#apt), [Yum](#yum), [pkg](#pkg), or [conda-forge](#conda-forge), and it comes preinstalled with [Postgres.app](#postgresapp) and many [hosted providers](#hosted-postgres). There are also instructions for [GitHub Actions](https://github.com/pgvector/setup-pgvector).

 ### Windows

 Ensure [C++ support in Visual Studio](https://learn.microsoft.com/en-us/cpp/build/building-on-the-command-line?view=msvc-170#download-and-install-the-tools) is installed and run `x64 Native Tools Command Prompt for VS [version]` as administrator. Then use `nmake` to build:

 ```cmd
-set "PGROOT=C:\Program Files\PostgreSQL\18"
+set "PGROOT=C:\Program Files\PostgreSQL\17"
 cd %TEMP%
-git clone --branch v0.8.2 https://github.com/pgvector/pgvector.git
+git clone --branch v0.8.0 https://github.com/pgvector/pgvector.git
 cd pgvector
 nmake /F Makefile.win
 nmake /F Makefile.win install
@@ -316,8 +314,6 @@ For a large number of workers, you may need to increase `max_parallel_workers` (

 The [index options](#index-options) also have a significant impact on build time (use the defaults unless seeing low recall)

-Use [binary quantization](#binary-quantization) for faster build times at scale
-
 ### Indexing Progress

 Check [indexing progress](https://www.postgresql.org/docs/current/progress-reporting.html#CREATE-INDEX-PROGRESS-REPORTING)
@@ -447,7 +443,13 @@ Exact indexes work well for conditions that match a low percentage of rows. Othe
 CREATE INDEX ON items USING hnsw (embedding vector_l2_ops);
 ```

-With approximate indexes, filtering is applied *after* the index is scanned. If a condition matches 10% of rows, with HNSW and the default `hnsw.ef_search` of 40, only 4 rows will match on average. For more rows, enable [iterative index scans](#iterative-index-scans), which will automatically scan more of the index when needed.
+With approximate indexes, filtering is applied *after* the index is scanned. If a condition matches 10% of rows, with HNSW and the default `hnsw.ef_search` of 40, only 4 rows will match on average. For more rows, increase `hnsw.ef_search`.
+
+```sql
+SET hnsw.ef_search = 200;
+```
+
+Starting with 0.8.0, you can enable [iterative index scans](#iterative-index-scans), which will automatically scan more of the index when needed.

 ```sql
 SET hnsw.iterative_scan = strict_order;
@@ -671,10 +673,6 @@ SHOW shared_buffers;

 Be sure to restart Postgres for changes to take effect.

-### Storing
-
-Use the `halfvec` type instead of `vector` for a smaller working set.
-
 ### Loading

 Use `COPY` for bulk loading data ([example](https://github.com/pgvector/pgvector-python/blob/master/examples/loading/example.py)).
@@ -689,8 +687,6 @@ Add any indexes *after* loading the initial data for best performance.

 See index build time for [HNSW](#index-build-time) and [IVFFlat](#index-build-time-1).

-Use [binary quantization](#binary-quantization) for smaller indexes and faster build times at scale.
-
 In production environments, create indexes concurrently to avoid blocking writes.

 ```sql
@@ -699,10 +695,10 @@ CREATE INDEX CONCURRENTLY ...

 ### Querying

-Use `EXPLAIN (ANALYZE, BUFFERS)` to debug performance.
+Use `EXPLAIN ANALYZE` to debug performance.

 ```sql
-EXPLAIN (ANALYZE, BUFFERS) SELECT * FROM items ORDER BY embedding <-> '[3,1,2]' LIMIT 5;
+EXPLAIN ANALYZE SELECT * FROM items ORDER BY embedding <-> '[3,1,2]' LIMIT 5;
 ```

 #### Exact Search
@@ -721,8 +717,6 @@ SELECT * FROM items ORDER BY embedding <#> '[3,1,2]' LIMIT 5;

 #### Approximate Search

-Use [binary quantization](#binary-quantization) with re-ranking to keep indexes in-memory at scale.
-
 To speed up queries with an IVFFlat index, increase the number of inverted lists (at the expense of recall).

 ```sql
@@ -738,20 +732,21 @@ REINDEX INDEX CONCURRENTLY index_name;
 VACUUM table_name;
 ```

-## Scaling
-
-For a smaller working set:
-
-1. Use the `halfvec` type instead of `vector` for tables
-2. Use [binary quantization](#binary-quantization) for indexes (with re-ranking for search)
-
-Scale vertically by increasing memory, CPU, and storage on a single instance. Use existing tools to [tune parameters](#tuning) and [monitor performance](#monitoring).
-
-Scale horizontally with [replicas](https://www.postgresql.org/docs/current/hot-standby.html), or use [Citus](https://github.com/citusdata/citus), [PgDog](https://github.com/pgdogdev/pgdog), or another approach for sharding ([example](https://github.com/pgvector/pgvector-python/blob/master/examples/citus/example.py)).
-
 ## Monitoring

-Use existing tools like [pg_stat_statements](https://www.postgresql.org/docs/current/pgstatstatements.html) or [PgHero](https://github.com/ankane/pghero) to monitor performance.
+Monitor performance with [pg_stat_statements](https://www.postgresql.org/docs/current/pgstatstatements.html) (be sure to add it to `shared_preload_libraries`).
+
+```sql
+CREATE EXTENSION pg_stat_statements;
+```
+
+Get the most time-consuming queries with:
+
+```sql
+SELECT query, calls, ROUND((total_plan_time + total_exec_time) / calls) AS avg_time_ms,
+    ROUND((total_plan_time + total_exec_time) / 60000) AS total_time_min
+    FROM pg_stat_statements ORDER BY total_plan_time + total_exec_time DESC LIMIT 20;
+```

 Monitor recall by comparing results from approximate search with exact search.

@@ -762,18 +757,23 @@ SELECT ...
 COMMIT;
 ```

+## Scaling
+
+Scale pgvector the same way you scale Postgres.
+
+Scale vertically by increasing memory, CPU, and storage on a single instance. Use existing tools to [tune parameters](#tuning) and [monitor performance](#monitoring).
+
+Scale horizontally with [replicas](https://www.postgresql.org/docs/current/hot-standby.html), or use [Citus](https://github.com/citusdata/citus) or another approach for sharding ([example](https://github.com/pgvector/pgvector-python/blob/master/examples/citus/example.py)).
+
 ## Languages

 Use pgvector from any language with a Postgres client. You can even generate and store vectors in one language and query them in another.

 Language | Libraries / Examples
 --- | ---
-Ada | [pgvector-ada](https://github.com/pgvector/pgvector-ada)
-Algol | [pgvector-algol](https://github.com/pgvector/pgvector-algol)
 C | [pgvector-c](https://github.com/pgvector/pgvector-c)
 C++ | [pgvector-cpp](https://github.com/pgvector/pgvector-cpp)
 C#, F#, Visual Basic | [pgvector-dotnet](https://github.com/pgvector/pgvector-dotnet)
-COBOL | [pgvector-cobol](https://github.com/pgvector/pgvector-cobol)
 Crystal | [pgvector-crystal](https://github.com/pgvector/pgvector-crystal)
 D | [pgvector-d](https://github.com/pgvector/pgvector-d)
 Dart | [pgvector-dart](https://github.com/pgvector/pgvector-dart)
@@ -790,18 +790,14 @@ Lisp | [pgvector-lisp](https://github.com/pgvector/pgvector-lisp)
 Lua | [pgvector-lua](https://github.com/pgvector/pgvector-lua)
 Nim | [pgvector-nim](https://github.com/pgvector/pgvector-nim)
 OCaml | [pgvector-ocaml](https://github.com/pgvector/pgvector-ocaml)
-Pascal | [pgvector-pascal](https://github.com/pgvector/pgvector-pascal)
 Perl | [pgvector-perl](https://github.com/pgvector/pgvector-perl)
 PHP | [pgvector-php](https://github.com/pgvector/pgvector-php)
-Prolog | [pgvector-prolog](https://github.com/pgvector/pgvector-prolog)
 Python | [pgvector-python](https://github.com/pgvector/pgvector-python)
 R | [pgvector-r](https://github.com/pgvector/pgvector-r)
-Racket | [pgvector-racket](https://github.com/pgvector/pgvector-racket)
 Raku | [pgvector-raku](https://github.com/pgvector/pgvector-raku)
 Ruby | [pgvector-ruby](https://github.com/pgvector/pgvector-ruby), [Neighbor](https://github.com/ankane/neighbor)
 Rust | [pgvector-rust](https://github.com/pgvector/pgvector-rust)
 Swift | [pgvector-swift](https://github.com/pgvector/pgvector-swift)
-Tcl | [pgvector-tcl](https://github.com/pgvector/pgvector-tcl)
 Zig | [pgvector-zig](https://github.com/pgvector/pgvector-zig)

 ## Frequently Asked Questions
@@ -816,7 +812,7 @@ Yes, pgvector uses the write-ahead log (WAL), which allows for replication and p

 #### What if I want to index vectors with more than 2,000 dimensions?

-You can use [half-precision vectors](#half-precision-vectors) or [half-precision indexing](#half-precision-indexing) to index up to 4,000 dimensions or [binary quantization](#binary-quantization) to index up to 64,000 dimensions. Other options are [indexing subvectors](#indexing-subvectors) (for models that support it) or [dimensionality reduction](https://en.wikipedia.org/wiki/Dimensionality_reduction).
+You can use [half-precision indexing](#half-precision-indexing) to index up to 4,000 dimensions or [binary quantization](#binary-quantization) to index up to 64,000 dimensions. Another option is [dimensionality reduction](https://en.wikipedia.org/wiki/Dimensionality_reduction).

 #### Can I store vectors with different dimensions in the same column?

@@ -875,8 +871,6 @@ No, but like other index types, you’ll likely see better performance if they d
 SELECT pg_size_pretty(pg_relation_size('index_name'));
 ```

-Use [half-precision indexing](#half-precision-indexing) or [binary quantization](#binary-quantization) for smaller indexes.
-
 ## Troubleshooting

 #### Why isn’t a query using an index?
@@ -1070,7 +1064,7 @@ l2_normalize(sparsevec) → sparsevec | Normalize with Euclidean norm | 0.7.0
 If your machine has multiple Postgres installations, specify the path to [pg_config](https://www.postgresql.org/docs/current/app-pgconfig.html) with:

 ```sh
-export PG_CONFIG=/Library/PostgreSQL/18/bin/pg_config
+export PG_CONFIG=/Library/PostgreSQL/17/bin/pg_config
 ```

 Then re-run the installation instructions (run `make clean` before `make` if needed). If `sudo` is needed for `make install`, use:
@@ -1081,11 +1075,11 @@ sudo --preserve-env=PG_CONFIG make install

 A few common paths on Mac are:

- EDB installer - `/Library/PostgreSQL/18/bin/pg_config`
- Homebrew (arm64) - `/opt/homebrew/opt/postgresql@18/bin/pg_config`
- Homebrew (x86-64) - `/usr/local/opt/postgresql@18/bin/pg_config`
+- EDB installer - `/Library/PostgreSQL/17/bin/pg_config`
+- Homebrew (arm64) - `/opt/homebrew/opt/postgresql@17/bin/pg_config`
+- Homebrew (x86-64) - `/usr/local/opt/postgresql@17/bin/pg_config`

-Note: Replace `18` with your Postgres server version
+Note: Replace `17` with your Postgres server version

 ### Missing Header

@@ -1094,10 +1088,10 @@ If compilation fails with `fatal error: postgres.h: No such file or directory`,
 For Ubuntu and Debian, use:

 ```sh
-sudo apt install postgresql-server-dev-18
+sudo apt install postgresql-server-dev-17
 ```

-Note: Replace `18` with your Postgres server version
+Note: Replace `17` with your Postgres server version

 ### Missing SDK

@@ -1144,32 +1138,17 @@ If installation fails with `Access is denied`, re-run the installation instructi
 Get the [Docker image](https://hub.docker.com/r/pgvector/pgvector) with:

 ```sh
-docker pull pgvector/pgvector:pg18-trixie
+docker pull pgvector/pgvector:pg17
 ```

-This adds pgvector to the [Postgres image](https://hub.docker.com/_/postgres) (replace `18` with your Postgres server version, and run it the same way).
-
-Supported tags are:
-
- `pg18-trixie`, `0.8.2-pg18-trixie`
- `pg18-bookworm`, `0.8.2-pg18-bookworm`, `pg18`, `0.8.2-pg18`
- `pg17-trixie`, `0.8.2-pg17-trixie`
- `pg17-bookworm`, `0.8.2-pg17-bookworm`, `pg17`, `0.8.2-pg17`
- `pg16-trixie`, `0.8.2-pg16-trixie`
- `pg16-bookworm`, `0.8.2-pg16-bookworm`, `pg16`, `0.8.2-pg16`
- `pg15-trixie`, `0.8.2-pg15-trixie`
- `pg15-bookworm`, `0.8.2-pg15-bookworm`, `pg15`, `0.8.2-pg15`
- `pg14-trixie`, `0.8.2-pg14-trixie`
- `pg14-bookworm`, `0.8.2-pg14-bookworm`, `pg14`, `0.8.2-pg14`
- `pg13-trixie`, `0.8.2-pg13-trixie`
- `pg13-bookworm`, `0.8.2-pg13-bookworm`, `pg13`, `0.8.2-pg13`
+This adds pgvector to the [Postgres image](https://hub.docker.com/_/postgres) (replace `17` with your Postgres server version, and run it the same way).

 You can also build the image manually:

 ```sh
-git clone --branch v0.8.2 https://github.com/pgvector/pgvector.git
+git clone --branch v0.8.0 https://github.com/pgvector/pgvector.git
 cd pgvector
-docker build --pull --build-arg PG_MAJOR=18 -t myuser/pgvector .
+docker build --pull --build-arg PG_MAJOR=17 -t myuser/pgvector .
 ```

 If you increase `maintenance_work_mem`, make sure `--shm-size` is at least that size to avoid an error with parallel HNSW index builds.
@@ -1186,7 +1165,7 @@ With Homebrew Postgres, you can use:
 brew install pgvector
 ```

-Note: This only adds it to the `postgresql@18` and `postgresql@17` formulas
+Note: This only adds it to the `postgresql@17` and `postgresql@14` formulas

 ### PGXN

@@ -1201,29 +1180,29 @@ pgxn install vector
 Debian and Ubuntu packages are available from the [PostgreSQL APT Repository](https://wiki.postgresql.org/wiki/Apt). Follow the [setup instructions](https://wiki.postgresql.org/wiki/Apt#Quickstart) and run:

 ```sh
-sudo apt install postgresql-18-pgvector
+sudo apt install postgresql-17-pgvector
 ```

-Note: Replace `18` with your Postgres server version
+Note: Replace `17` with your Postgres server version

 ### Yum

 RPM packages are available from the [PostgreSQL Yum Repository](https://yum.postgresql.org/). Follow the [setup instructions](https://www.postgresql.org/download/linux/redhat/) for your distribution and run:

 ```sh
-sudo yum install pgvector_18
+sudo yum install pgvector_17
 # or
-sudo dnf install pgvector_18
+sudo dnf install pgvector_17
 ```

-Note: Replace `18` with your Postgres server version
+Note: Replace `17` with your Postgres server version

 ### pkg

 Install the FreeBSD package with:

 ```sh
-pkg install postgresql17-pgvector
+pkg install postgresql16-pgvector
 ```

 or the port with:
@@ -1233,14 +1212,6 @@ cd /usr/ports/databases/pgvector
 make install
 ```

-### APK
-
-Install the Alpine package with:
-
-```sh
-apk add postgresql-pgvector
-```
-
 ### conda-forge

 With Conda Postgres, install from [conda-forge](https://anaconda.org/conda-forge/pgvector) with:
@@ -1329,7 +1300,7 @@ make clean && PG_CFLAGS="-DUSE_ASSERT_CHECKING" make && make install
 To enable benchmarking:

 ```sh
-make clean && PG_CFLAGS="-DHNSW_BENCH -DIVFFLAT_BENCH" make && make install
+make clean && PG_CFLAGS="-DIVFFLAT_BENCH" make && make install
 ```

 To show memory usage:
--- a/sql/vector--0.8.0--0.8.1.sql
+++ b/sql/vector--0.8.0--0.8.1.sql
@@ -1,2 +0,0 @@
-- complain if script is sourced in psql, rather than via CREATE EXTENSION
-\echo Use "ALTER EXTENSION vector UPDATE TO '0.8.1'" to load this file. \quit
--- a/sql/vector--0.8.1--0.8.2.sql
+++ b/sql/vector--0.8.1--0.8.2.sql
@@ -1,2 +0,0 @@
-- complain if script is sourced in psql, rather than via CREATE EXTENSION
-\echo Use "ALTER EXTENSION vector UPDATE TO '0.8.2'" to load this file. \quit
--- a/src/bitutils.c
+++ b/src/bitutils.c
@@ -31,12 +31,10 @@
 #define BIT_TARGET_CLONES
 #endif

-/* Use built-ins when possible for Postgres < 19 for inlining */
-#if PG_VERSION_NUM >= 190000
-#define popcount64(x) pg_popcount64(x)
-#elif defined(HAVE__BUILTIN_POPCOUNT) && (defined(HAVE_LONG_INT_64) || SIZEOF_LONG == 8)
+/* Use built-ins when possible for inlining */
+#if defined(HAVE__BUILTIN_POPCOUNT) && defined(HAVE_LONG_INT_64)
 #define popcount64(x) __builtin_popcountl(x)
-#elif defined(HAVE__BUILTIN_POPCOUNT) && (defined(HAVE_LONG_LONG_INT_64) || SIZEOF_LONG_LONG == 8)
+#elif defined(HAVE__BUILTIN_POPCOUNT) && defined(HAVE_LONG_LONG_INT_64)
 #define popcount64(x) __builtin_popcountll(x)
 #elif !defined(_MSC_VER)
 /* Fails to resolve with MSVC */
@@ -171,7 +169,7 @@ BitJaccardDistanceAvx512Popcount(uint32 bytes, unsigned char *ax, unsigned char
 #endif

 TARGET_XSAVE static bool
-SupportsAvx512Popcount(void)
+SupportsAvx512Popcount()
 {
 	unsigned int exx[4] = {0, 0, 0, 0};

--- a/src/bitvec.c
+++ b/src/bitvec.c
@@ -2,7 +2,6 @@

 #include "bitutils.h"
 #include "bitvec.h"
-#include "fmgr.h"
 #include "utils/varbit.h"
 #include "vector.h"

--- a/src/halfutils.c
+++ b/src/halfutils.c
@@ -1,7 +1,5 @@
 #include "postgres.h"

-#include <math.h>
-
 #include "halfutils.h"
 #include "halfvec.h"

--- a/src/halfvec.c
+++ b/src/halfvec.c
@@ -13,20 +13,12 @@
 #include "port.h"				/* for strtof() */
 #include "sparsevec.h"
 #include "utils/array.h"
+#include "utils/builtins.h"
 #include "utils/float.h"
-#include "utils/fmgrprotos.h"
 #include "utils/lsyscache.h"
-#include "utils/varbit.h"
+#include "utils/numeric.h"
 #include "vector.h"

-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif
-
-#if PG_VERSION_NUM >= 170000
-#include "parser/scansup.h"
-#endif
-
 #define STATE_DIMS(x) (ARR_DIMS(x)[0] - 1)
 #define CreateStateDatums(dim) palloc(sizeof(Datum) * (dim + 1))

@@ -137,9 +129,9 @@ InitHalfVector(int dim)
 	return result;
 }

-#if PG_VERSION_NUM >= 170000
-#define halfvec_isspace(ch) scanner_isspace(ch)
-#else
+/*
+ * Check for whitespace, since array_isspace() is static
+ */
 static inline bool
 halfvec_isspace(char ch)
 {
@@ -152,7 +144,6 @@ halfvec_isspace(char ch)
 		return true;
 	return false;
 }
-#endif

 /*
 * Check state array
@@ -907,21 +898,8 @@ halfvec_binary_quantize(PG_FUNCTION_ARGS)
 	half	   *ax = a->x;
 	VarBit	   *result = InitBitVector(a->dim);
 	unsigned char *rx = VARBITS(result);
-	int			i = 0;
-	int			count = (a->dim / 8) * 8;

-	/* Auto-vectorized on aarch64 */
-	for (; i < count; i += 8)
-	{
-		unsigned char result_byte = 0;
-
-		for (int j = 0; j < 8; j++)
-			result_byte |= (HalfToFloat4(ax[i + j]) > 0) << (7 - j);
-
-		rx[i / 8] = result_byte;
-	}
-
-	for (; i < a->dim; i++)
+	for (int i = 0; i < a->dim; i++)
 		rx[i / 8] |= (HalfToFloat4(ax[i]) > 0) << (7 - (i % 8));

 	PG_RETURN_VARBIT_P(result);
--- a/src/hnsw.c
+++ b/src/hnsw.c
@@ -1,25 +1,18 @@
 #include "postgres.h"

 #include <float.h>
-#include <limits.h>
 #include <math.h>

 #include "access/amapi.h"
-#include "access/genam.h"
 #include "access/reloptions.h"
 #include "commands/progress.h"
 #include "commands/vacuum.h"
-#include "fmgr.h"
 #include "hnsw.h"
 #include "miscadmin.h"
-#include "nodes/pg_list.h"
-#include "storage/lwlock.h"
 #include "utils/float.h"
 #include "utils/guc.h"
-#include "utils/relcache.h"
 #include "utils/selfuncs.h"
 #include "utils/spccache.h"
-#include "vector.h"

 #if PG_VERSION_NUM < 150000
 #define MarkGUCPrefixReserved(x) EmitWarningsOnPlaceholders(x)
@@ -59,20 +52,12 @@ HnswInitLockTranche(void)
 								  sizeof(int) * 1,
 								  &found);
 	if (!found)
-	{
-#if PG_VERSION_NUM >= 190000
-		tranche_ids[0] = LWLockNewTrancheId("HnswBuild");
-#else
 		tranche_ids[0] = LWLockNewTrancheId();
-#endif
-	}
 	hnsw_lock_tranche_id = tranche_ids[0];
 	LWLockRelease(AddinShmemInitLock);

-#if PG_VERSION_NUM < 190000
 	/* Per-backend registration of the tranche ID */
 	LWLockRegisterTranche(hnsw_lock_tranche_id, "HnswBuild");
-#endif
 }

 /*
@@ -145,7 +130,7 @@ hnswcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 	Relation	index;

 	/* Never use index without order */
-	if (path->indexorderbys == NIL)
+	if (path->indexorderbys == NULL)
 	{
 		*indexStartupCost = get_float8_infinity();
 		*indexTotalCost = get_float8_infinity();
@@ -267,68 +252,6 @@ FUNCTION_PREFIX PG_FUNCTION_INFO_V1(hnswhandler);
 Datum
 hnswhandler(PG_FUNCTION_ARGS)
 {
-#if PG_VERSION_NUM >= 190000
-	static const IndexAmRoutine amroutine = {
-		.type = T_IndexAmRoutine,
-		.amstrategies = 0,
-		.amsupport = 3,
-		.amoptsprocnum = 0,
-		.amcanorder = false,
-		.amcanorderbyop = true,
-		.amcanhash = false,
-		.amconsistentequality = false,
-		.amconsistentordering = false,
-		.amcanbackward = false,
-		.amcanunique = false,
-		.amcanmulticol = false,
-		.amoptionalkey = true,
-		.amsearcharray = false,
-		.amsearchnulls = false,
-		.amstorage = false,
-		.amclusterable = false,
-		.ampredlocks = false,
-		.amcanparallel = false,
-		.amcanbuildparallel = true,
-		.amcaninclude = false,
-#if PG_VERSION_NUM >= 170000
-		.amusemaintenanceworkmem = true,
-#else
-		.amusemaintenanceworkmem = false,
-#endif
-		.amsummarizing = false,
-		.amparallelvacuumoptions = VACUUM_OPTION_PARALLEL_BULKDEL,
-		.amkeytype = InvalidOid,
-
-		.ambuild = hnswbuild,
-		.ambuildempty = hnswbuildempty,
-		.aminsert = hnswinsert,
-		.aminsertcleanup = NULL,
-		.ambulkdelete = hnswbulkdelete,
-		.amvacuumcleanup = hnswvacuumcleanup,
-		.amcanreturn = NULL,
-		.amcostestimate = hnswcostestimate,
-		.amgettreeheight = NULL,
-		.amoptions = hnswoptions,
-		.amproperty = NULL,
-		.ambuildphasename = hnswbuildphasename,
-		.amvalidate = hnswvalidate,
-		.amadjustmembers = NULL,
-		.ambeginscan = hnswbeginscan,
-		.amrescan = hnswrescan,
-		.amgettuple = hnswgettuple,
-		.amgetbitmap = NULL,
-		.amendscan = hnswendscan,
-		.ammarkpos = NULL,
-		.amrestrpos = NULL,
-		.amestimateparallelscan = NULL,
-		.aminitparallelscan = NULL,
-		.amparallelrescan = NULL,
-		.amtranslatestrategy = NULL,
-		.amtranslatecmptype = NULL,
-	};
-
-	PG_RETURN_POINTER(&amroutine);
-#else
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);

 	amroutine->amstrategies = 0;
@@ -355,11 +278,7 @@ hnswhandler(PG_FUNCTION_ARGS)
 	amroutine->amcanbuildparallel = true;
 #endif
 	amroutine->amcaninclude = false;
-#if PG_VERSION_NUM >= 170000
-	amroutine->amusemaintenanceworkmem = true;
-#else
-	amroutine->amusemaintenanceworkmem = false;
-#endif
+	amroutine->amusemaintenanceworkmem = false; /* not used during VACUUM */
 #if PG_VERSION_NUM >= 160000
 	amroutine->amsummarizing = false;
 #endif
@@ -406,5 +325,4 @@ hnswhandler(PG_FUNCTION_ARGS)
 #endif

 	PG_RETURN_POINTER(amroutine);
-#endif
 }
--- a/src/hnsw.h
+++ b/src/hnsw.h
@@ -3,35 +3,15 @@

 #include "postgres.h"

-#include <math.h>
-
 #include "access/genam.h"
 #include "access/parallel.h"
 #include "lib/pairingheap.h"
 #include "nodes/execnodes.h"
 #include "port.h"				/* for random() */
-#include "storage/bufpage.h"
-#include "storage/condition_variable.h"
-#include "storage/lwlock.h"
-#include "storage/s_lock.h"
 #include "utils/relptr.h"
 #include "utils/sampling.h"
 #include "vector.h"

-#ifdef HNSW_BENCH
-#include "portability/instr_time.h"
-#endif
-
-#if PG_VERSION_NUM >= 190000
-typedef Pointer Item;
-#endif
-
-#if PG_VERSION_NUM >= 170000
-#define HnswTidStore TidStore
-#else
-#define HnswTidStore tidhash_hash
-#endif
-
 #define HNSW_MAX_DIM 2000
 #define HNSW_MAX_NNZ 1000

@@ -88,21 +68,6 @@ typedef Pointer Item;
 #define HnswPageGetOpaque(page)	((HnswPageOpaque) PageGetSpecialPointer(page))
 #define HnswPageGetMeta(page)	((HnswMetaPageData *) PageGetContents(page))

-#ifdef HNSW_BENCH
-#define HnswBench(name, code) \
-	do { \
-		instr_time	start; \
-		instr_time	duration; \
-		INSTR_TIME_SET_CURRENT(start); \
-		(code); \
-		INSTR_TIME_SET_CURRENT(duration); \
-		INSTR_TIME_SUBTRACT(duration, start); \
-		elog(INFO, "%s: %.3f ms", name, INSTR_TIME_GET_MILLISEC(duration)); \
-	} while (0)
-#else
-#define HnswBench(name, code) (code)
-#endif
-
 #if PG_VERSION_NUM >= 150000
 #define RandomDouble() pg_prng_double(&pg_global_prng_state)
 #define SeedRandom(seed) pg_prng_seed(&pg_global_prng_state, seed)
@@ -397,6 +362,13 @@ typedef union
 	ItemPointerData indextid;
 }			HnswUnvisited;

+typedef struct HnswReadStreamData
+{
+	HnswUnvisited *unvisited;
+	int			unvisitedLength;
+	int			visited;
+}			HnswReadStreamData;
+
 typedef struct HnswScanOpaqueData
 {
 	const		HnswTypeInfo *typeInfo;
@@ -433,11 +405,10 @@ typedef struct HnswVacuumState
 	HnswSupport support;

 	/* Variables */
-	struct HnswTidStore *deleted;
+	struct tidhash_hash *deleted;
 	BufferAccessStrategy bas;
 	HnswNeighborTuple ntup;
 	HnswElementData highestPoint;
-	HnswElementData fallbackPoint;

 	/* Memory */
 	MemoryContext tmpCtx;
@@ -453,14 +424,14 @@ bool		HnswCheckNorm(HnswSupport * support, Datum value);
 Buffer		HnswNewBuffer(Relation index, ForkNumber forkNum);
 void		HnswInitPage(Buffer buf, Page page);
 void		HnswInit(void);
-List	   *HnswSearchLayer(char *base, HnswQuery * q, List *ep, int ef, int lc, Relation index, HnswSupport * support, int m, bool inserting, HnswElement skipElement, visited_hash * v, pairingheap **discarded, bool initVisited, int64 *tuples);
+List	   *HnswSearchLayer(char *base, HnswQuery * q, List *ep, int ef, int lc, Relation index, HnswSupport * support, int m, bool inserting, HnswElement skipElement, visited_hash * v, pairingheap **discarded, bool initVisited, int64 *tuples, bool maintenance);
 HnswElement HnswGetEntryPoint(Relation index);
 void		HnswGetMetaPageInfo(Relation index, int *m, HnswElement * entryPoint);
 void	   *HnswAlloc(HnswAllocator * allocator, Size size);
 HnswElement HnswInitElement(char *base, ItemPointer tid, int m, double ml, int maxLevel, HnswAllocator * alloc);
 HnswElement HnswInitElementFromBlock(BlockNumber blkno, OffsetNumber offno);
-void		HnswFindElementNeighbors(char *base, HnswElement element, HnswElement entryPoint, Relation index, HnswSupport * support, int m, int efConstruction, bool existing);
-HnswSearchCandidate *HnswEntryCandidate(char *base, HnswElement entryPoint, HnswQuery * q, Relation index, HnswSupport * support, bool loadVec);
+void		HnswFindElementNeighbors(char *base, HnswElement element, HnswElement entryPoint, Relation index, HnswSupport * support, int m, int efConstruction, bool existing, bool maintenance);
+HnswSearchCandidate *HnswEntryCandidate(char *base, HnswElement em, HnswQuery * q, Relation rel, HnswSupport * support, bool loadVec);
 void		HnswUpdateMetaPage(Relation index, int updateEntry, HnswElement entryPoint, BlockNumber insertPage, ForkNumber forkNum, bool building);
 void		HnswSetNeighborTuple(char *base, HnswNeighborTuple ntup, HnswElement e, int m);
 void		HnswAddHeapTid(HnswElement element, ItemPointer heaptid);
--- a/src/hnswbuild.c
+++ b/src/hnswbuild.c
@@ -36,14 +36,11 @@
 */
 #include "postgres.h"

-#include <limits.h>
+#include <math.h>

-#include "access/genam.h"
 #include "access/parallel.h"
-#include "access/relscan.h"
 #include "access/table.h"
 #include "access/tableam.h"
-#include "access/tupdesc.h"
 #include "access/xact.h"
 #include "access/xloginsert.h"
 #include "catalog/index.h"
@@ -51,19 +48,11 @@
 #include "commands/progress.h"
 #include "hnsw.h"
 #include "miscadmin.h"
-#include "nodes/execnodes.h"
 #include "optimizer/optimizer.h"
 #include "storage/bufmgr.h"
-#include "storage/condition_variable.h"
 #include "tcop/tcopprot.h"
 #include "utils/datum.h"
 #include "utils/memutils.h"
-#include "utils/rel.h"
-#include "utils/snapmgr.h"
-
-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif

 #if PG_VERSION_NUM >= 140000
 #include "utils/backend_progress.h"
@@ -80,8 +69,6 @@
 #define PARALLEL_KEY_HNSW_AREA			UINT64CONST(0xA000000000000002)
 #define PARALLEL_KEY_QUERY_TEXT			UINT64CONST(0xA000000000000003)

-#define HNSW_MAX_GRAPH_MEMORY (SIZE_MAX / 2)
-
 /*
 * Create the metapage
 */
@@ -411,7 +398,7 @@ UpdateNeighborsInMemory(char *base, HnswSupport * support, HnswElement e, int m)
 * Update graph in memory
 */
 static void
-UpdateGraphInMemory(HnswSupport * support, HnswElement element, int m, HnswElement entryPoint, HnswBuildState * buildstate)
+UpdateGraphInMemory(HnswSupport * support, HnswElement element, int m, int efConstruction, HnswElement entryPoint, HnswBuildState * buildstate)
 {
 	HnswGraph  *graph = buildstate->graph;
 	char	   *base = buildstate->hnswarea;
@@ -470,10 +457,10 @@ InsertTupleInMemory(HnswBuildState * buildstate, HnswElement element)
 	}

 	/* Find neighbors for element */
-	HnswFindElementNeighbors(base, element, entryPoint, NULL, support, m, efConstruction, false);
+	HnswFindElementNeighbors(base, element, entryPoint, NULL, support, m, efConstruction, false, true);

 	/* Update graph in memory */
-	UpdateGraphInMemory(support, element, m, entryPoint, buildstate);
+	UpdateGraphInMemory(support, element, m, efConstruction, entryPoint, buildstate);

 	/* Release entry lock */
 	LWLockRelease(entryLock);
@@ -494,7 +481,6 @@ InsertTuple(Relation index, Datum *values, bool *isnull, ItemPointer heaptid, Hn
 	LWLock	   *flushLock = &graph->flushLock;
 	char	   *base = buildstate->hnswarea;
 	Datum		value;
-	Size		memoryMargin;

 	/* Form index value */
 	if (!HnswFormIndexValue(&value, values, isnull, buildstate->typeInfo, support))
@@ -503,9 +489,6 @@ InsertTuple(Relation index, Datum *values, bool *isnull, ItemPointer heaptid, Hn
 	/* Get datum size */
 	valueSize = VARSIZE_ANY(DatumGetPointer(value));

-	/* In a parallel build, add a margin so allocations never fail */
-	memoryMargin = base == NULL ? 0 : 1024 * 1024;
-
 	/* Ensure graph not flushed when inserting */
 	LWLockAcquire(flushLock, LW_SHARED);

@@ -527,7 +510,7 @@ InsertTuple(Relation index, Datum *values, bool *isnull, ItemPointer heaptid, Hn
 	 * Check that we have enough memory available for the new element now that
 	 * we have the allocator lock, and flush pages if needed.
 	 */
-	if (graph->memoryUsed + memoryMargin >= graph->memoryTotal)
+	if (graph->memoryUsed >= graph->memoryTotal)
 	{
 		LWLockRelease(&graph->allocatorLock);

@@ -562,7 +545,7 @@ InsertTuple(Relation index, Datum *values, bool *isnull, ItemPointer heaptid, Hn

 	/* Copy the datum */
 	memcpy(valuePtr, DatumGetPointer(value), valueSize);
-	HnswPtrStore(base, element->value, (char *) valuePtr);
+	HnswPtrStore(base, element->value, valuePtr);

 	/* Create a lock for the element */
 	LWLockInitialize(&element->lock, hnsw_lock_tranche_id);
@@ -620,7 +603,7 @@ InitGraph(HnswGraph * graph, char *base, Size memoryTotal)
 	HnswPtrStore(base, graph->head, (HnswElement) NULL);
 	HnswPtrStore(base, graph->entryPoint, (HnswElement) NULL);
 	graph->memoryUsed = 0;
-	graph->memoryTotal = Min(memoryTotal, HNSW_MAX_GRAPH_MEMORY);
+	graph->memoryTotal = memoryTotal;
 	graph->flushed = false;
 	graph->indtuples = 0;
 	SpinLockInit(&graph->lock);
@@ -661,17 +644,9 @@ static void *
 HnswSharedMemoryAlloc(Size size, void *state)
 {
 	HnswBuildState *buildstate = (HnswBuildState *) state;
-	Size		alignedSize = MAXALIGN(size);
-	void	   *chunk;
+	void	   *chunk = buildstate->hnswarea + buildstate->graph->memoryUsed;

-	if (alignedSize > 1024 * 1024)
-		elog(ERROR, "hnsw allocation too large");
-
-	if (buildstate->graph->memoryUsed + alignedSize > buildstate->graph->memoryTotal)
-		elog(ERROR, "hnsw allocator out of memory");
-
-	chunk = buildstate->hnswarea + buildstate->graph->memoryUsed;
-	buildstate->graph->memoryUsed += alignedSize;
+	buildstate->graph->memoryUsed += MAXALIGN(size);
 	return chunk;
 }

@@ -803,11 +778,7 @@ HnswParallelScanAndInsert(Relation heapRel, Relation indexRel, HnswShared * hnsw
 	buildstate.hnswarea = hnswarea;
 	InitAllocator(&buildstate.allocator, &HnswSharedMemoryAlloc, &buildstate);
 	scan = table_beginscan_parallel(heapRel,
-									ParallelTableScanFromHnswShared(hnswshared)
-#if PG_VERSION_NUM >= 190000
-									,SO_NONE
-#endif
-		);
+									ParallelTableScanFromHnswShared(hnswshared));
 	reltuples = table_index_build_scan(heapRel, indexRel, indexInfo,
 									   true, progress, BuildCallback,
 									   (void *) &buildstate, scan);
@@ -961,8 +932,6 @@ HnswBeginParallel(HnswBuildState * buildstate, bool isconcurrent, int request)
 	if (esthnswarea > estother)
 		esthnswarea -= estother;

-	esthnswarea = Min(esthnswarea, HNSW_MAX_GRAPH_MEMORY);
-
 	shm_toc_estimate_chunk(&pcxt->estimator, esthnswarea);
 	shm_toc_estimate_keys(&pcxt->estimator, 2);

@@ -1005,7 +974,8 @@ HnswBeginParallel(HnswBuildState * buildstate, bool isconcurrent, int request)
 								  snapshot);

 	hnswarea = (char *) shm_toc_allocate(pcxt->toc, esthnswarea);
-	InitGraph(&hnswshared->graphData, hnswarea, esthnswarea);
+	/* Report less than allocated so never fails */
+	InitGraph(&hnswshared->graphData, hnswarea, esthnswarea - 1024 * 1024);

 	/*
 	 * Avoid base address for relptr for Postgres < 14.5
@@ -1084,7 +1054,7 @@ ComputeParallelWorkers(Relation heap, Relation index)
 * Build graph
 */
 static void
-BuildGraph(HnswBuildState * buildstate)
+BuildGraph(HnswBuildState * buildstate, ForkNumber forkNum)
 {
 	int			parallel_workers = 0;

@@ -1132,7 +1102,7 @@ BuildIndex(Relation heap, Relation index, IndexInfo *indexInfo,

 	InitBuildState(buildstate, heap, index, indexInfo, forkNum);

-	BuildGraph(buildstate);
+	BuildGraph(buildstate, forkNum);

 	if (RelationNeedsWAL(index) || forkNum == INIT_FORKNUM)
 		log_newpage_range(index, forkNum, 0, RelationGetNumberOfBlocksInFork(index, forkNum), true);
--- a/src/hnswinsert.c
+++ b/src/hnswinsert.c
@@ -1,19 +1,13 @@
 #include "postgres.h"

-#include "access/genam.h"
+#include <math.h>
+
 #include "access/generic_xlog.h"
 #include "hnsw.h"
-#include "nodes/execnodes.h"
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
-#include "storage/lwlock.h"
 #include "utils/datum.h"
 #include "utils/memutils.h"
-#include "utils/rel.h"
-
-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif

 /*
 * Get the insert page
@@ -666,7 +660,7 @@ FindDuplicateOnDisk(Relation index, HnswElement element, bool building)
 * Update graph on disk
 */
 static void
-UpdateGraphOnDisk(Relation index, HnswSupport * support, HnswElement element, int m, HnswElement entryPoint, bool building)
+UpdateGraphOnDisk(Relation index, HnswSupport * support, HnswElement element, int m, int efConstruction, HnswElement entryPoint, bool building)
 {
 	BlockNumber newInsertPage = InvalidBlockNumber;

@@ -714,7 +708,7 @@ HnswInsertTupleOnDisk(Relation index, HnswSupport * support, Datum value, ItemPo

 	/* Create an element */
 	element = HnswInitElement(base, heaptid, m, HnswGetMl(m), HnswGetMaxLevel(m), NULL);
-	HnswPtrStore(base, element->value, (char *) DatumGetPointer(value));
+	HnswPtrStore(base, element->value, DatumGetPointer(value));

 	/* Prevent concurrent inserts when likely updating entry point */
 	if (entryPoint == NULL || element->level > entryPoint->level)
@@ -731,10 +725,10 @@ HnswInsertTupleOnDisk(Relation index, HnswSupport * support, Datum value, ItemPo
 	}

 	/* Find neighbors for element */
-	HnswFindElementNeighbors(base, element, entryPoint, index, support, m, efConstruction, false);
+	HnswFindElementNeighbors(base, element, entryPoint, index, support, m, efConstruction, false, building);

 	/* Update graph on disk */
-	UpdateGraphOnDisk(index, support, element, m, entryPoint, building);
+	UpdateGraphOnDisk(index, support, element, m, efConstruction, entryPoint, building);

 	/* Release lock */
 	UnlockPage(index, HNSW_UPDATE_LOCK, lockmode);
--- a/src/hnswscan.c
+++ b/src/hnswscan.c
@@ -1,23 +1,12 @@
 #include "postgres.h"

-#include <limits.h>
-
-#include "access/genam.h"
 #include "access/relscan.h"
 #include "hnsw.h"
-#include "lib/pairingheap.h"
-#include "miscadmin.h"
-#include "nodes/pg_list.h"
 #include "pgstat.h"
+#include "storage/bufmgr.h"
 #include "storage/lmgr.h"
 #include "utils/float.h"
 #include "utils/memutils.h"
-#include "utils/relcache.h"
-#include "utils/snapmgr.h"
-
-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif

 /*
 * Algorithm 5 from paper
@@ -48,11 +37,11 @@ GetScanItems(IndexScanDesc scan, Datum value)

 	for (int lc = entryPoint->level; lc >= 1; lc--)
 	{
-		w = HnswSearchLayer(base, q, ep, 1, lc, index, support, m, false, NULL, NULL, NULL, true, NULL);
+		w = HnswSearchLayer(base, q, ep, 1, lc, index, support, m, false, NULL, NULL, NULL, true, NULL, false);
 		ep = w;
 	}

-	return HnswSearchLayer(base, q, ep, hnsw_ef_search, 0, index, support, m, false, NULL, &so->v, hnsw_iterative_scan != HNSW_ITERATIVE_SCAN_OFF ? &so->discarded : NULL, true, &so->tuples);
+	return HnswSearchLayer(base, q, ep, hnsw_ef_search, 0, index, support, m, false, NULL, &so->v, hnsw_iterative_scan != HNSW_ITERATIVE_SCAN_OFF ? &so->discarded : NULL, true, &so->tuples, false);
 }

 /*
@@ -83,7 +72,7 @@ ResumeScanItems(IndexScanDesc scan)
 		ep = lappend(ep, sc);
 	}

-	return HnswSearchLayer(base, &so->q, ep, batch_size, 0, index, &so->support, so->m, false, NULL, &so->v, &so->discarded, false, &so->tuples);
+	return HnswSearchLayer(base, &so->q, ep, batch_size, 0, index, &so->support, so->m, false, NULL, &so->v, &so->discarded, false, &so->tuples, false);
 }

 /*
@@ -153,7 +142,7 @@ hnswbeginscan(Relation index, int nkeys, int norderbys)
 	/* Calculate max memory */
 	/* Add 256 extra bytes to fill last block when close */
 	maxMemory = (double) work_mem * hnsw_scan_mem_multiplier * 1024.0 + 256;
-	so->maxMemory = Min(maxMemory, (double) (SIZE_MAX / 2));
+	so->maxMemory = Min(maxMemory, (double) SIZE_MAX);

 	scan->opaque = so;

@@ -204,10 +193,6 @@ hnswgettuple(IndexScanDesc scan, ScanDirection dir)

 		/* Count index scan for stats */
 		pgstat_count_index_scan(scan->indexRelation);
-#if PG_VERSION_NUM >= 180000
-		if (scan->instrument)
-			scan->instrument->nsearches++;
-#endif

 		/* Safety check */
 		if (scan->orderByData == NULL)
--- a/src/hnswutils.c
+++ b/src/hnswutils.c
@@ -2,23 +2,21 @@

 #include <math.h>

-#include "access/genam.h"
 #include "access/generic_xlog.h"
+#include "catalog/pg_type.h"
+#include "catalog/pg_type_d.h"
 #include "common/hashfn.h"
 #include "fmgr.h"
 #include "hnsw.h"
 #include "lib/pairingheap.h"
-#include "nodes/pg_list.h"
-#include "port/atomics.h"
 #include "sparsevec.h"
 #include "storage/bufmgr.h"
 #include "utils/datum.h"
 #include "utils/memdebug.h"
 #include "utils/rel.h"
-#include "vector.h"

-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
+#if PG_VERSION_NUM >= 170000
+#include "storage/read_stream.h"
 #endif

 #if PG_VERSION_NUM < 170000
@@ -262,7 +260,7 @@ HnswInitElement(char *base, ItemPointer heaptid, int m, double ml, int maxLevel,

 	HnswInitNeighbors(base, element, m, allocator);

-	HnswPtrStore(base, element->value, (char *) NULL);
+	HnswPtrStore(base, element->value, (Pointer) NULL);

 	return element;
 }
@@ -288,7 +286,7 @@ HnswInitElementFromBlock(BlockNumber blkno, OffsetNumber offno)
 	element->blkno = blkno;
 	element->offno = offno;
 	HnswPtrStore(base, element->neighbors, (HnswNeighborArrayPtr *) NULL);
-	HnswPtrStore(base, element->value, (char *) NULL);
+	HnswPtrStore(base, element->value, (Pointer) NULL);
 	return element;
 }

@@ -514,7 +512,7 @@ HnswLoadElementFromTuple(HnswElement element, HnswElementTuple etup, bool loadHe
 		char	   *base = NULL;
 		Datum		value = datumCopy(PointerGetDatum(&etup->data), false, -1);

-		HnswPtrStore(base, element->value, (char *) DatumGetPointer(value));
+		HnswPtrStore(base, element->value, DatumGetPointer(value));
 	}
 }

@@ -531,14 +529,12 @@ HnswGetDistance(Datum a, Datum b, HnswSupport * support)
 * Load an element and optionally get its distance from q
 */
 static void
-HnswLoadElementImpl(BlockNumber blkno, OffsetNumber offno, double *distance, HnswQuery * q, Relation index, HnswSupport * support, bool loadVec, double *maxDistance, HnswElement * element)
+HnswLoadElementImpl(Buffer buf, OffsetNumber offno, double *distance, HnswQuery * q, Relation index, HnswSupport * support, bool loadVec, double *maxDistance, HnswElement * element)
 {
-	Buffer		buf;
 	Page		page;
 	HnswElementTuple etup;

 	/* Read vector */
-	buf = ReadBuffer(index, blkno);
 	LockBuffer(buf, BUFFER_LOCK_SHARE);
 	page = BufferGetPage(buf);

@@ -546,9 +542,6 @@ HnswLoadElementImpl(BlockNumber blkno, OffsetNumber offno, double *distance, Hns

 	Assert(HnswIsElementTuple(etup));

-	if (unlikely(etup->deleted))
-		elog(ERROR, "cannot load deleted element");
-
 	/* Calculate distance */
 	if (distance != NULL)
 	{
@@ -562,7 +555,7 @@ HnswLoadElementImpl(BlockNumber blkno, OffsetNumber offno, double *distance, Hns
 	if (distance == NULL || maxDistance == NULL || *distance < *maxDistance)
 	{
 		if (*element == NULL)
-			*element = HnswInitElementFromBlock(blkno, offno);
+			*element = HnswInitElementFromBlock(BufferGetBlockNumber(buf), offno);

 		HnswLoadElementFromTuple(*element, etup, true, loadVec);
 	}
@@ -576,7 +569,9 @@ HnswLoadElementImpl(BlockNumber blkno, OffsetNumber offno, double *distance, Hns
 void
 HnswLoadElement(HnswElement element, double *distance, HnswQuery * q, Relation index, HnswSupport * support, bool loadVec, double *maxDistance)
 {
-	HnswLoadElementImpl(element->blkno, element->offno, distance, q, index, support, loadVec, maxDistance, &element);
+	Buffer		buf = ReadBuffer(index, element->blkno);
+
+	HnswLoadElementImpl(buf, element->offno, distance, q, index, support, loadVec, maxDistance, &element);
 }

 /*
@@ -816,11 +811,31 @@ HnswLoadUnvisitedFromDisk(HnswElement element, HnswUnvisited * unvisited, int *u
 	}
 }

+#if PG_VERSION_NUM >= 170000
+/*
+ * Get next block number for read stream
+ */
+static BlockNumber
+HnswReadStreamNextBlock(ReadStream *stream, void *callback_private_data, void *per_buffer_data)
+{
+	HnswReadStreamData *streamData = callback_private_data;
+	OffsetNumber *offno = per_buffer_data;
+	HnswUnvisited *uv;
+
+	if (streamData->visited == streamData->unvisitedLength)
+		return InvalidBlockNumber;
+
+	uv = &streamData->unvisited[streamData->visited++];
+	*offno = ItemPointerGetOffsetNumber(&uv->indextid);
+	return ItemPointerGetBlockNumber(&uv->indextid);
+}
+#endif
+
 /*
 * Algorithm 2 from paper
 */
 List *
-HnswSearchLayer(char *base, HnswQuery * q, List *ep, int ef, int lc, Relation index, HnswSupport * support, int m, bool inserting, HnswElement skipElement, visited_hash * v, pairingheap **discarded, bool initVisited, int64 *tuples)
+HnswSearchLayer(char *base, HnswQuery * q, List *ep, int ef, int lc, Relation index, HnswSupport * support, int m, bool inserting, HnswElement skipElement, visited_hash * v, pairingheap **discarded, bool initVisited, int64 *tuples, bool maintenance)
 {
 	List	   *w = NIL;
 	pairingheap *C = pairingheap_allocate(CompareNearestCandidates, NULL);
@@ -835,6 +850,18 @@ HnswSearchLayer(char *base, HnswQuery * q, List *ep, int ef, int lc, Relation in
 	int			unvisitedLength;
 	bool		inMemory = index == NULL;

+#if PG_VERSION_NUM >= 170000
+	HnswReadStreamData streamData;
+	ReadStream *stream = NULL;
+
+	if (!inMemory)
+	{
+		int			flags = maintenance ? READ_STREAM_MAINTENANCE : READ_STREAM_DEFAULT;
+
+		stream = read_stream_begin_relation(flags, NULL, index, MAIN_FORKNUM, HnswReadStreamNextBlock, &streamData, sizeof(OffsetNumber));
+	}
+#endif
+
 	if (v == NULL)
 	{
 		v = &vh;
@@ -897,8 +924,18 @@ HnswSearchLayer(char *base, HnswQuery * q, List *ep, int ef, int lc, Relation in
 		if (inMemory)
 			HnswLoadUnvisitedFromMemory(base, cElement, unvisited, &unvisitedLength, v, lc, localNeighborhood, neighborhoodSize);
 		else
+		{
 			HnswLoadUnvisitedFromDisk(cElement, unvisited, &unvisitedLength, v, index, m, lm, lc);

+#if PG_VERSION_NUM >= 170000
+			read_stream_reset(stream);
+
+			streamData.unvisited = unvisited;
+			streamData.unvisitedLength = unvisitedLength;
+			streamData.visited = 0;
+#endif
+		}
+
 		/* OK to count elements instead of tuples */
 		if (tuples != NULL)
 			(*tuples) += unvisitedLength;
@@ -919,19 +956,30 @@ HnswSearchLayer(char *base, HnswQuery * q, List *ep, int ef, int lc, Relation in
 			}
 			else
 			{
+				Buffer		buf;
+				OffsetNumber offno;
+
+#if PG_VERSION_NUM >= 170000
+				void	   *offnoPtr;
+
+				buf = read_stream_next_buffer(stream, &offnoPtr);
+				offno = *((OffsetNumber *) offnoPtr);
+#else
 				ItemPointer indextid = &unvisited[i].indextid;
-				BlockNumber blkno = ItemPointerGetBlockNumber(indextid);
-				OffsetNumber offno = ItemPointerGetOffsetNumber(indextid);
+
+				buf = ReadBuffer(index, ItemPointerGetBlockNumber(indextid));
+				offno = ItemPointerGetOffsetNumber(indextid);
+#endif

 				/* Avoid any allocations if not adding */
 				eElement = NULL;
-				HnswLoadElementImpl(blkno, offno, &eDistance, q, index, support, inserting, alwaysAdd || discarded != NULL ? NULL : &f->distance, &eElement);
+				HnswLoadElementImpl(buf, offno, &eDistance, q, index, support, inserting, alwaysAdd || discarded != NULL ? NULL : &f->distance, &eElement);

 				if (eElement == NULL)
 					continue;
 			}

-			if (!(eDistance < f->distance || alwaysAdd))
+			if (eElement == NULL || !(eDistance < f->distance || alwaysAdd))
 			{
 				if (discarded != NULL)
 				{
@@ -981,6 +1029,11 @@ HnswSearchLayer(char *base, HnswQuery * q, List *ep, int ef, int lc, Relation in
 		w = lappend(w, sc);
 	}

+#if PG_VERSION_NUM >= 170000
+	if (!inMemory)
+		read_stream_end(stream);
+#endif
+
 	return w;
 }

@@ -1276,7 +1329,7 @@ PrecomputeHash(char *base, HnswElement element)
 * Algorithm 1 from paper
 */
 void
-HnswFindElementNeighbors(char *base, HnswElement element, HnswElement entryPoint, Relation index, HnswSupport * support, int m, int efConstruction, bool existing)
+HnswFindElementNeighbors(char *base, HnswElement element, HnswElement entryPoint, Relation index, HnswSupport * support, int m, int efConstruction, bool existing, bool maintenance)
 {
 	List	   *ep;
 	List	   *w;
@@ -1303,7 +1356,7 @@ HnswFindElementNeighbors(char *base, HnswElement element, HnswElement entryPoint
 	/* 1st phase: greedy search to insert level */
 	for (int lc = entryLevel; lc >= level + 1; lc--)
 	{
-		w = HnswSearchLayer(base, &q, ep, 1, lc, index, support, m, true, skipElement, NULL, NULL, true, NULL);
+		w = HnswSearchLayer(base, &q, ep, 1, lc, index, support, m, true, skipElement, NULL, NULL, true, NULL, maintenance);
 		ep = w;
 	}

@@ -1322,7 +1375,7 @@ HnswFindElementNeighbors(char *base, HnswElement element, HnswElement entryPoint
 		List	   *lw = NIL;
 		ListCell   *lc2;

-		w = HnswSearchLayer(base, &q, ep, efConstruction, lc, index, support, m, true, skipElement, NULL, NULL, true, NULL);
+		w = HnswSearchLayer(base, &q, ep, efConstruction, lc, index, support, m, true, skipElement, NULL, NULL, true, NULL, maintenance);

 		/* Convert search candidates to candidates */
 		foreach(lc2, w)
--- a/src/hnswvacuum.c
+++ b/src/hnswvacuum.c
@@ -1,24 +1,13 @@
 #include "postgres.h"

-#include "access/genam.h"
+#include <math.h>
+
 #include "access/generic_xlog.h"
 #include "commands/vacuum.h"
 #include "hnsw.h"
-#include "nodes/pg_list.h"
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
 #include "utils/memutils.h"
-#include "utils/rel.h"
-
-#if PG_VERSION_NUM >= 170000
-#include "access/tidstore.h"
-#include "miscadmin.h"
-#include "postmaster/autovacuum.h"
-#endif
-
-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif

 #if PG_VERSION_NUM >= 180000
 #define vacuum_delay_point() vacuum_delay_point(false)
@@ -28,13 +17,9 @@
 * Check if deleted list contains an index TID
 */
 static bool
-DeletedContains(HnswTidStore * deleted, ItemPointer indextid)
+DeletedContains(tidhash_hash * deleted, ItemPointer indextid)
 {
-#if PG_VERSION_NUM >= 170000
-	return TidStoreIsMember(deleted, indextid);
-#else
 	return tidhash_lookup(deleted, *indextid) != NULL;
-#endif
 }

 /*
@@ -47,20 +32,17 @@ RemoveHeapTids(HnswVacuumState * vacuumstate)
 {
 	BlockNumber blkno = HNSW_HEAD_BLKNO;
 	HnswElement highestPoint = &vacuumstate->highestPoint;
-	HnswElement fallbackPoint = &vacuumstate->fallbackPoint;
 	Relation	index = vacuumstate->index;
 	BufferAccessStrategy bas = vacuumstate->bas;
+	HnswElement entryPoint = HnswGetEntryPoint(vacuumstate->index);
 	IndexBulkDeleteResult *stats = vacuumstate->stats;

-	/* Store separately since HnswElement level is uint8 */
+	/* Store separately since highestPoint.level is uint8 */
 	int			highestLevel = -1;
-	int			fallbackLevel = -1;

-	/* Initialize highest point and fallback point */
+	/* Initialize highest point */
 	highestPoint->blkno = InvalidBlockNumber;
 	highestPoint->offno = InvalidOffsetNumber;
-	fallbackPoint->blkno = InvalidBlockNumber;
-	fallbackPoint->offno = InvalidOffsetNumber;

 	while (BlockNumberIsValid(blkno))
 	{
@@ -70,10 +52,6 @@ RemoveHeapTids(HnswVacuumState * vacuumstate)
 		OffsetNumber offno;
 		OffsetNumber maxoffno;
 		bool		updated = false;
-#if PG_VERSION_NUM >= 170000
-		OffsetNumber deletedoffs[MaxOffsetNumber];
-		int			ndeletedoffs = 0;
-#endif

 		vacuum_delay_point();

@@ -127,9 +105,6 @@ RemoveHeapTids(HnswVacuumState * vacuumstate)

 			if (!ItemPointerIsValid(&etup->heaptids[0]))
 			{
-#if PG_VERSION_NUM >= 170000
-				deletedoffs[ndeletedoffs++] = offno;
-#else
 				ItemPointerData ip;
 				bool		found;

@@ -138,39 +113,17 @@ RemoveHeapTids(HnswVacuumState * vacuumstate)

 				tidhash_insert(vacuumstate->deleted, ip, &found);
 				Assert(!found);
-#endif
 			}
-			else if (etup->level > highestLevel)
+			else if (etup->level > highestLevel && !(entryPoint != NULL && blkno == entryPoint->blkno && offno == entryPoint->offno))
 			{
-				if (BlockNumberIsValid(highestPoint->blkno))
-				{
-					/* Current highest point becomes fallback */
-					fallbackPoint->blkno = highestPoint->blkno;
-					fallbackPoint->offno = highestPoint->offno;
-					fallbackPoint->level = highestPoint->level;
-					fallbackLevel = highestLevel;
-				}
-
-				/* Keep track of highest point */
+				/* Keep track of highest non-entry point */
 				highestPoint->blkno = blkno;
 				highestPoint->offno = offno;
 				highestPoint->level = etup->level;
 				highestLevel = etup->level;
 			}
-			else if (etup->level > fallbackLevel)
-			{
-				/* Keep track of second highest point */
-				fallbackPoint->blkno = blkno;
-				fallbackPoint->offno = offno;
-				fallbackPoint->level = etup->level;
-				fallbackLevel = etup->level;
-			}
 		}

-#if PG_VERSION_NUM >= 170000
-		TidStoreSetBlockOffsets(vacuumstate->deleted, blkno, deletedoffs, ndeletedoffs);
-#endif
-
 		blkno = HnswPageGetOpaque(page)->nextblkno;

 		if (updated)
@@ -180,10 +133,6 @@ RemoveHeapTids(HnswVacuumState * vacuumstate)

 		UnlockReleaseBuffer(buf);
 	}
-
-#ifdef HNSW_MEMORY
-	elog(INFO, "memory: %zu KB", MemoryContextMemAllocated(CurrentMemoryContext, true) / 1024);
-#endif
 }

 /*
@@ -225,12 +174,7 @@ NeedsUpdated(HnswVacuumState * vacuumstate, HnswElement element)
 	/* Also update if layer 0 is not full */
 	/* This could indicate too many candidates being deleted during insert */
 	if (!needsUpdated)
-	{
-		/* Keep clang-tidy happy */
-		Assert(ntup->count > 0);
-
 		needsUpdated = !ItemPointerIsValid(&ntup->indextids[ntup->count - 1]);
-	}

 	UnlockReleaseBuffer(buf);

@@ -264,7 +208,7 @@ RepairGraphElement(HnswVacuumState * vacuumstate, HnswElement element, HnswEleme
 	element->heaptidsLength = 0;

 	/* Find neighbors for element, skipping itself */
-	HnswFindElementNeighbors(base, element, entryPoint, index, support, m, efConstruction, true);
+	HnswFindElementNeighbors(base, element, entryPoint, index, support, m, efConstruction, true, true);

 	/* Zero memory for each element */
 	MemSet(ntup, 0, HNSW_TUPLE_ALLOC_SIZE);
@@ -315,27 +259,12 @@ RepairGraphEntryPoint(HnswVacuumState * vacuumstate)
 		/* Get a shared lock */
 		LockPage(index, HNSW_UPDATE_LOCK, ShareLock);

-		/* Get latest entry point */
-		entryPoint = HnswGetEntryPoint(index);
+		/* Load element */
+		HnswLoadElement(highestPoint, NULL, NULL, index, support, true, NULL);

-		/* Use fallback point if highest point is entry point */
-		if (entryPoint != NULL && entryPoint->blkno == highestPoint->blkno && entryPoint->offno == highestPoint->offno)
-		{
-			highestPoint = &vacuumstate->fallbackPoint;
-
-			if (!BlockNumberIsValid(highestPoint->blkno))
-				highestPoint = NULL;
-		}
-
-		if (highestPoint != NULL)
-		{
-			/* Load element */
-			HnswLoadElement(highestPoint, NULL, NULL, index, support, true, NULL);
-
-			/* Repair if needed */
-			if (NeedsUpdated(vacuumstate, highestPoint))
-				RepairGraphElement(vacuumstate, highestPoint, entryPoint);
-		}
+		/* Repair if needed */
+		if (NeedsUpdated(vacuumstate, highestPoint))
+			RepairGraphElement(vacuumstate, highestPoint, HnswGetEntryPoint(index));

 		/* Release lock */
 		UnlockPage(index, HNSW_UPDATE_LOCK, ShareLock);
@@ -502,99 +431,6 @@ RepairGraph(HnswVacuumState * vacuumstate)
 		/* Reset memory context */
 		MemoryContextSwitchTo(oldCtx);
 		MemoryContextReset(vacuumstate->tmpCtx);
-
-#ifdef HNSW_VACUUM_PROGRESS
-		if (!BlockNumberIsValid(blkno) || ((blkno - HNSW_HEAD_BLKNO) % 1000 == 0 && blkno != HNSW_HEAD_BLKNO))
-		{
-			BlockNumber totalBlocks = RelationGetNumberOfBlocks(index);
-			BlockNumber currentBlocks = BlockNumberIsValid(blkno) ? blkno : totalBlocks;
-
-			elog(INFO, "hnsw vacuum progress: %.1f%%", 100.0 * currentBlocks / totalBlocks);
-		}
-#endif
-	}
-}
-
-/*
- * Confirm graph was repaired
- */
-static void
-ConfirmRepaired(HnswVacuumState * vacuumstate)
-{
-	BlockNumber blkno = HNSW_HEAD_BLKNO;
-	Relation	index = vacuumstate->index;
-	BufferAccessStrategy bas = vacuumstate->bas;
-
-	while (BlockNumberIsValid(blkno))
-	{
-		Buffer		buf;
-		Page		page;
-		OffsetNumber offno;
-		OffsetNumber maxoffno;
-
-		vacuum_delay_point();
-
-		buf = ReadBufferExtended(index, MAIN_FORKNUM, blkno, RBM_NORMAL, bas);
-		LockBuffer(buf, BUFFER_LOCK_SHARE);
-		page = BufferGetPage(buf);
-		maxoffno = PageGetMaxOffsetNumber(page);
-
-		/* Iterate over nodes */
-		for (offno = FirstOffsetNumber; offno <= maxoffno; offno = OffsetNumberNext(offno))
-		{
-			HnswElementTuple etup = (HnswElementTuple) PageGetItem(page, PageGetItemId(page, offno));
-			HnswNeighborTuple ntup;
-			Buffer		nbuf;
-			Page		npage;
-			BlockNumber neighborPage;
-			OffsetNumber neighborOffno;
-
-			/* Skip neighbor tuples */
-			if (!HnswIsElementTuple(etup))
-				continue;
-
-			/* Skip if being deleted */
-			if (!ItemPointerIsValid(&etup->heaptids[0]))
-				continue;
-
-			/* Get neighbor page */
-			neighborPage = ItemPointerGetBlockNumber(&etup->neighbortid);
-			neighborOffno = ItemPointerGetOffsetNumber(&etup->neighbortid);
-
-			if (neighborPage == blkno)
-			{
-				nbuf = buf;
-				npage = page;
-			}
-			else
-			{
-				nbuf = ReadBufferExtended(index, MAIN_FORKNUM, neighborPage, RBM_NORMAL, bas);
-				LockBuffer(nbuf, BUFFER_LOCK_SHARE);
-				npage = BufferGetPage(nbuf);
-			}
-
-			ntup = (HnswNeighborTuple) PageGetItem(npage, PageGetItemId(npage, neighborOffno));
-
-			/* Check neighbors */
-			for (int i = 0; i < ntup->count; i++)
-			{
-				ItemPointer indextid = &ntup->indextids[i];
-
-				if (!ItemPointerIsValid(indextid))
-					continue;
-
-				/* Check if in deleted list */
-				if (DeletedContains(vacuumstate->deleted, indextid))
-					elog(ERROR, "hnsw graph not repaired");
-			}
-
-			if (nbuf != buf)
-				UnlockReleaseBuffer(nbuf);
-		}
-
-		blkno = HnswPageGetOpaque(page)->nextblkno;
-
-		UnlockReleaseBuffer(buf);
 	}
 }

@@ -688,9 +524,8 @@ MarkDeleted(HnswVacuumState * vacuumstate)
 			ntup = (HnswNeighborTuple) PageGetItem(npage, PageGetItemId(npage, neighborOffno));

 			/* Overwrite element */
-			/* Use memset instead of MemSet to keep clang-tidy happy */
 			etup->deleted = 1;
-			memset(&etup->data, 0, VARSIZE_ANY(&etup->data));
+			MemSet(&etup->data, 0, VARSIZE_ANY(&etup->data));

 			/* Overwrite neighbors */
 			for (int i = 0; i < ntup->count; i++)
@@ -761,11 +596,7 @@ InitVacuumState(HnswVacuumState * vacuumstate, IndexVacuumInfo *info, IndexBulkD
 	HnswGetMetaPageInfo(index, &vacuumstate->m, NULL);

 	/* Create hash table */
-#if PG_VERSION_NUM >= 170000
-	vacuumstate->deleted = TidStoreCreateLocal((AmAutoVacuumWorkerProcess() && autovacuum_work_mem != -1) ? autovacuum_work_mem : maintenance_work_mem, true);
-#else
 	vacuumstate->deleted = tidhash_create(CurrentMemoryContext, 256, NULL);
-#endif
 }

 /*
@@ -774,11 +605,7 @@ InitVacuumState(HnswVacuumState * vacuumstate, IndexVacuumInfo *info, IndexBulkD
 static void
 FreeVacuumState(HnswVacuumState * vacuumstate)
 {
-#if PG_VERSION_NUM >= 170000
-	TidStoreDestroy(vacuumstate->deleted);
-#else
 	tidhash_destroy(vacuumstate->deleted);
-#endif
 	FreeAccessStrategy(vacuumstate->bas);
 	pfree(vacuumstate->ntup);
 	MemoryContextDelete(vacuumstate->tmpCtx);
@@ -796,16 +623,13 @@ hnswbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 	InitVacuumState(&vacuumstate, info, stats, callback, callback_state);

 	/* Pass 1: Remove heap TIDs */
-	HnswBench("RemoveHeapTids", RemoveHeapTids(&vacuumstate));
+	RemoveHeapTids(&vacuumstate);

 	/* Pass 2: Repair graph */
-	HnswBench("RepairGraph", RepairGraph(&vacuumstate));
+	RepairGraph(&vacuumstate);

-	/* Pass 3: Confirm repaired */
-	HnswBench("ConfirmRepaired", ConfirmRepaired(&vacuumstate));
-
-	/* Pass 4: Mark as deleted */
-	HnswBench("MarkDeleted", MarkDeleted(&vacuumstate));
+	/* Pass 3: Mark as deleted */
+	MarkDeleted(&vacuumstate);

 	FreeVacuumState(&vacuumstate);

--- a/src/ivfbuild.c
+++ b/src/ivfbuild.c
@@ -2,37 +2,23 @@

 #include <float.h>

-#include "access/genam.h"
-#include "access/generic_xlog.h"
-#include "access/itup.h"
-#include "access/relscan.h"
 #include "access/table.h"
 #include "access/tableam.h"
-#include "access/tupdesc.h"
 #include "access/parallel.h"
 #include "access/xact.h"
-#include "access/xloginsert.h"
+#include "bitvec.h"
 #include "catalog/index.h"
 #include "catalog/pg_operator_d.h"
 #include "catalog/pg_type_d.h"
 #include "commands/progress.h"
-#include "fmgr.h"
+#include "halfvec.h"
 #include "ivfflat.h"
 #include "miscadmin.h"
-#include "nodes/execnodes.h"
 #include "optimizer/optimizer.h"
 #include "storage/bufmgr.h"
-#include "storage/condition_variable.h"
 #include "tcop/tcopprot.h"
 #include "utils/memutils.h"
-#include "utils/rel.h"
-#include "utils/sampling.h"
-#include "utils/snapmgr.h"
-#include "utils/tuplesort.h"
-
-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif
+#include "vector.h"

 #if PG_VERSION_NUM >= 140000
 #include "utils/backend_progress.h"
@@ -63,13 +49,15 @@ AddSample(Datum *values, IvfflatBuildState * buildstate)
 	Datum		value = PointerGetDatum(PG_DETOAST_DATUM(values[0]));

 	/*
-	 * Check with KMEANS_NORM_PROC that the value can be normalized since
-	 * spherical distance function expects unit vectors
+	 * Normalize with KMEANS_NORM_PROC since spherical distance function
+	 * expects unit vectors
 	 */
 	if (buildstate->kmeansnormprocinfo != NULL)
 	{
 		if (!IvfflatCheckNorm(buildstate->kmeansnormprocinfo, buildstate->collation, value))
 			return;
+
+		value = IvfflatNormValue(buildstate->typeInfo, buildstate->collation, value);
 	}

 	if (samples->length < targsamples)
@@ -80,7 +68,7 @@ AddSample(Datum *values, IvfflatBuildState * buildstate)
 	else
 	{
 		if (buildstate->rowstoskip < 0)
-			buildstate->rowstoskip = reservoir_get_next_S(&buildstate->rstate, buildstate->samplerows, targsamples);
+			buildstate->rowstoskip = reservoir_get_next_S(&buildstate->rstate, samples->length, targsamples);

 		if (buildstate->rowstoskip <= 0)
 		{
@@ -96,9 +84,6 @@ AddSample(Datum *values, IvfflatBuildState * buildstate)

 		buildstate->rowstoskip -= 1;
 	}
-
-	/* Increment after reservoir_get_next_S */
-	buildstate->samplerows += 1;
 }

 /*
@@ -135,7 +120,6 @@ SampleRows(IvfflatBuildState * buildstate)
 	int			targsamples = buildstate->samples->maxlen;
 	BlockNumber totalblocks = RelationGetNumberOfBlocks(buildstate->heap);

-	buildstate->samplerows = 0;
 	buildstate->rowstoskip = -1;

 	BlockSampler_Init(&buildstate->bs, totalblocks, targsamples, RandomInt());
@@ -145,24 +129,8 @@ SampleRows(IvfflatBuildState * buildstate)
 	{
 		BlockNumber targblock = BlockSampler_Next(&buildstate->bs);

-		/* Set anyvisible to false like table_index_build_scan */
 		table_index_build_range_scan(buildstate->heap, buildstate->index, buildstate->indexInfo,
-									 false, false, false, targblock, 1, SampleCallback, (void *) buildstate, NULL);
-	}
-
-	/* Normalize if needed */
-	if (buildstate->kmeansnormprocinfo != NULL)
-	{
-		VectorArray samples = buildstate->samples;
-
-		for (int i = 0; i < samples->length; i++)
-		{
-			Datum		value = PointerGetDatum(VectorArrayGet(samples, i));
-			Datum		normValue = IvfflatNormValue(buildstate->typeInfo, buildstate->collation, value);
-
-			VectorArraySet(samples, i, DatumGetPointer(normValue));
-			pfree(DatumGetPointer(normValue));
-		}
+									 false, true, false, targblock, 1, SampleCallback, (void *) buildstate, NULL);
 	}
 }

@@ -170,7 +138,7 @@ SampleRows(IvfflatBuildState * buildstate)
 * Add tuple to sort
 */
 static void
-AddTupleToSort(ItemPointer tid, Datum *values, IvfflatBuildState * buildstate)
+AddTupleToSort(Relation index, ItemPointer tid, Datum *values, IvfflatBuildState * buildstate)
 {
 	double		distance;
 	double		minDistance = DBL_MAX;
@@ -247,7 +215,7 @@ BuildCallback(Relation index, ItemPointer tid, Datum *values,
 	oldCtx = MemoryContextSwitchTo(buildstate->tmpCtx);

 	/* Add tuple to sort */
-	AddTupleToSort(tid, values, buildstate);
+	AddTupleToSort(index, tid, values, buildstate);

 	/* Reset memory context */
 	MemoryContextSwitchTo(oldCtx);
@@ -393,13 +361,9 @@ InitBuildState(IvfflatBuildState * buildstate, Relation heap, Relation index, In
 	TupleDescInitEntry(buildstate->sortdesc, (AttrNumber) 1, "list", INT4OID, -1, 0);
 	TupleDescInitEntry(buildstate->sortdesc, (AttrNumber) 2, "tid", TIDOID, -1, 0);
 	TupleDescInitEntry(buildstate->sortdesc, (AttrNumber) 3, "vector", TupleDescAttr(buildstate->tupdesc, 0)->atttypid, -1, 0);
-#if PG_VERSION_NUM >= 190000
-	TupleDescFinalize(buildstate->sortdesc);
-#endif

 	buildstate->slot = MakeSingleTupleTableSlot(buildstate->sortdesc, &TTSOpsVirtual);

-	/* TODO Ensure within maintenance_work_mem */
 	buildstate->centers = VectorArrayInit(buildstate->lists, buildstate->dimensions, buildstate->typeInfo->itemSize(buildstate->dimensions));
 	buildstate->listInfo = palloc(sizeof(ListInfo) * buildstate->lists);

@@ -458,7 +422,7 @@ ComputeCenters(IvfflatBuildState * buildstate)
 	buildstate->samples = VectorArrayInit(numSamples, buildstate->dimensions, buildstate->centers->itemsize);
 	if (buildstate->heap != NULL)
 	{
-		IvfflatBench("sample rows", SampleRows(buildstate));
+		SampleRows(buildstate);

 		if (buildstate->samples->length < buildstate->lists)
 		{
@@ -506,8 +470,8 @@ CreateMetaPage(Relation index, int dimensions, int lists, ForkNumber forkNum)
 * Create list pages
 */
 static void
-CreateListPages(Relation index, VectorArray centers, int lists,
-				ForkNumber forkNum, ListInfo * *listInfo)
+CreateListPages(Relation index, VectorArray centers, int dimensions,
+				int lists, ForkNumber forkNum, ListInfo * *listInfo)
 {
 	Buffer		buf;
 	Page		page;
@@ -673,11 +637,7 @@ IvfflatParallelScanAndSort(IvfflatSpool * ivfspool, IvfflatShared * ivfshared, S
 	ivfspool->sortstate = InitBuildSortState(buildstate.sortdesc, sortmem, coordinate);
 	buildstate.sortstate = ivfspool->sortstate;
 	scan = table_beginscan_parallel(ivfspool->heap,
-									ParallelTableScanFromIvfflatShared(ivfshared)
-#if PG_VERSION_NUM >= 190000
-									,SO_NONE
-#endif
-		);
+									ParallelTableScanFromIvfflatShared(ivfshared));
 	reltuples = table_index_build_scan(ivfspool->heap, ivfspool->index, indexInfo,
 									   true, progress, BuildCallback,
 									   (void *) &buildstate, scan);
@@ -1044,7 +1004,7 @@ BuildIndex(Relation heap, Relation index, IndexInfo *indexInfo,

 	/* Create pages */
 	CreateMetaPage(index, buildstate->dimensions, buildstate->lists, forkNum);
-	CreateListPages(index, buildstate->centers, buildstate->lists, forkNum, &buildstate->listInfo);
+	CreateListPages(index, buildstate->centers, buildstate->dimensions, buildstate->lists, forkNum, &buildstate->listInfo);
 	CreateEntryPages(buildstate, forkNum);

 	/* Write WAL for initialization fork since GenericXLog functions do not */
--- a/src/ivfflat.c
+++ b/src/ivfflat.c
@@ -3,19 +3,14 @@
 #include <float.h>

 #include "access/amapi.h"
-#include "access/genam.h"
 #include "access/reloptions.h"
 #include "commands/progress.h"
 #include "commands/vacuum.h"
-#include "fmgr.h"
 #include "ivfflat.h"
-#include "nodes/pg_list.h"
 #include "utils/float.h"
 #include "utils/guc.h"
-#include "utils/relcache.h"
 #include "utils/selfuncs.h"
 #include "utils/spccache.h"
-#include "vector.h"

 #if PG_VERSION_NUM < 150000
 #define MarkGUCPrefixReserved(x) EmitWarningsOnPlaceholders(x)
@@ -97,7 +92,7 @@ ivfflatcostestimate(PlannerInfo *root, IndexPath *path, double loop_count,
 	Relation	index;

 	/* Never use index without order */
-	if (path->indexorderbys == NIL)
+	if (path->indexorderbys == NULL)
 	{
 		*indexStartupCost = get_float8_infinity();
 		*indexTotalCost = get_float8_infinity();
@@ -184,64 +179,6 @@ FUNCTION_PREFIX PG_FUNCTION_INFO_V1(ivfflathandler);
 Datum
 ivfflathandler(PG_FUNCTION_ARGS)
 {
-#if PG_VERSION_NUM >= 190000
-	static const IndexAmRoutine amroutine = {
-		.type = T_IndexAmRoutine,
-		.amstrategies = 0,
-		.amsupport = 5,
-		.amoptsprocnum = 0,
-		.amcanorder = false,
-		.amcanorderbyop = true,
-		.amcanhash = false,
-		.amconsistentequality = false,
-		.amconsistentordering = false,
-		.amcanbackward = false,
-		.amcanunique = false,
-		.amcanmulticol = false,
-		.amoptionalkey = true,
-		.amsearcharray = false,
-		.amsearchnulls = false,
-		.amstorage = false,
-		.amclusterable = false,
-		.ampredlocks = false,
-		.amcanparallel = false,
-		.amcanbuildparallel = true,
-		.amcaninclude = false,
-		.amusemaintenanceworkmem = false,
-		.amsummarizing = false,
-		.amparallelvacuumoptions = VACUUM_OPTION_PARALLEL_BULKDEL,
-		.amkeytype = InvalidOid,
-
-		.ambuild = ivfflatbuild,
-		.ambuildempty = ivfflatbuildempty,
-		.aminsert = ivfflatinsert,
-		.aminsertcleanup = NULL,
-		.ambulkdelete = ivfflatbulkdelete,
-		.amvacuumcleanup = ivfflatvacuumcleanup,
-		.amcanreturn = NULL,
-		.amcostestimate = ivfflatcostestimate,
-		.amgettreeheight = NULL,
-		.amoptions = ivfflatoptions,
-		.amproperty = NULL,
-		.ambuildphasename = ivfflatbuildphasename,
-		.amvalidate = ivfflatvalidate,
-		.amadjustmembers = NULL,
-		.ambeginscan = ivfflatbeginscan,
-		.amrescan = ivfflatrescan,
-		.amgettuple = ivfflatgettuple,
-		.amgetbitmap = NULL,
-		.amendscan = ivfflatendscan,
-		.ammarkpos = NULL,
-		.amrestrpos = NULL,
-		.amestimateparallelscan = NULL,
-		.aminitparallelscan = NULL,
-		.amparallelrescan = NULL,
-		.amtranslatestrategy = NULL,
-		.amtranslatecmptype = NULL,
-	};
-
-	PG_RETURN_POINTER(&amroutine);
-#else
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);

 	amroutine->amstrategies = 0;
@@ -315,5 +252,4 @@ ivfflathandler(PG_FUNCTION_ARGS)
 #endif

 	PG_RETURN_POINTER(amroutine);
-#endif
 }
--- a/src/ivfflat.h
+++ b/src/ivfflat.h
@@ -9,15 +9,10 @@
 #include "lib/pairingheap.h"
 #include "nodes/execnodes.h"
 #include "port.h"				/* for random() */
-#include "storage/condition_variable.h"
 #include "utils/sampling.h"
 #include "utils/tuplesort.h"
 #include "vector.h"

-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif
-
 #if PG_VERSION_NUM >= 150000
 #include "common/pg_prng.h"
 #endif
@@ -26,10 +21,6 @@
 #include "portability/instr_time.h"
 #endif

-#if PG_VERSION_NUM >= 190000
-typedef Pointer Item;
-#endif
-
 #define IVFFLAT_MAX_DIM 2000

 /* Support functions */
@@ -214,8 +205,7 @@ typedef struct IvfflatBuildState
 	/* Sampling */
 	BlockSamplerData bs;
 	ReservoirStateData rstate;
-	double		samplerows;
-	double		rowstoskip;
+	int			rowstoskip;

 	/* Sorting */
 	Tuplesortstate *sortstate;
--- a/src/ivfinsert.c
+++ b/src/ivfinsert.c
@@ -2,16 +2,11 @@

 #include <float.h>

-#include "access/genam.h"
 #include "access/generic_xlog.h"
-#include "access/itup.h"
-#include "fmgr.h"
 #include "ivfflat.h"
-#include "nodes/execnodes.h"
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
 #include "utils/memutils.h"
-#include "utils/rel.h"

 /*
 * Find the list that minimizes the distance function
@@ -70,7 +65,7 @@ FindInsertPage(Relation index, Datum *values, BlockNumber *insertPage, ListInfo
 * Insert a tuple into the index
 */
 static void
-InsertTuple(Relation index, Datum *values, bool *isnull, ItemPointer heap_tid)
+InsertTuple(Relation index, Datum *values, bool *isnull, ItemPointer heap_tid, Relation heapRel)
 {
 	const		IvfflatTypeInfo *typeInfo = IvfflatGetTypeInfo(index);
 	IndexTuple	itup;
@@ -209,7 +204,7 @@ ivfflatinsert(Relation index, Datum *values, bool *isnull, ItemPointer heap_tid,
 	oldCtx = MemoryContextSwitchTo(insertCtx);

 	/* Insert tuple */
-	InsertTuple(index, values, isnull, heap_tid);
+	InsertTuple(index, values, isnull, heap_tid, heap);

 	/* Delete memory context */
 	MemoryContextSwitchTo(oldCtx);
--- a/src/ivfkmeans.c
+++ b/src/ivfkmeans.c
@@ -1,19 +1,17 @@
 #include "postgres.h"

 #include <float.h>
-#include <limits.h>
 #include <math.h>

-#include "access/genam.h"
-#include "fmgr.h"
+#include "bitvec.h"
+#include "halfutils.h"
+#include "halfvec.h"
 #include "ivfflat.h"
 #include "miscadmin.h"
+#include "utils/builtins.h"
+#include "utils/datum.h"
 #include "utils/memutils.h"
-#include "utils/relcache.h"
-
-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif
+#include "vector.h"

 /*
 * Initialize with kmeans++
--- a/src/ivfscan.c
+++ b/src/ivfscan.c
@@ -2,26 +2,15 @@

 #include <float.h>

-#include "access/genam.h"
-#include "access/itup.h"
 #include "access/relscan.h"
-#include "access/tupdesc.h"
 #include "catalog/pg_operator_d.h"
 #include "catalog/pg_type_d.h"
-#include "fmgr.h"
 #include "lib/pairingheap.h"
 #include "ivfflat.h"
 #include "miscadmin.h"
 #include "pgstat.h"
 #include "storage/bufmgr.h"
 #include "utils/memutils.h"
-#include "utils/rel.h"
-#include "utils/snapmgr.h"
-#include "utils/tuplesort.h"
-
-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif

 #define GetScanList(ptr) pairingheap_container(IvfflatScanList, ph_node, ptr)
 #define GetScanListConst(ptr) pairingheap_const_container(IvfflatScanList, ph_node, ptr)
@@ -298,9 +287,6 @@ ivfflatbeginscan(Relation index, int nkeys, int norderbys)
 	so->tupdesc = CreateTemplateTupleDesc(2);
 	TupleDescInitEntry(so->tupdesc, (AttrNumber) 1, "distance", FLOAT8OID, -1, 0);
 	TupleDescInitEntry(so->tupdesc, (AttrNumber) 2, "heaptid", TIDOID, -1, 0);
-#if PG_VERSION_NUM >= 190000
-	TupleDescFinalize(so->tupdesc);
-#endif

 	/* Prep sort */
 	so->sortstate = InitScanSortState(so->tupdesc);
@@ -369,10 +355,6 @@ ivfflatgettuple(IndexScanDesc scan, ScanDirection dir)

 		/* Count index scan for stats */
 		pgstat_count_index_scan(scan->indexRelation);
-#if PG_VERSION_NUM >= 180000
-		if (scan->instrument)
-			scan->instrument->nsearches++;
-#endif

 		/* Safety check */
 		if (scan->orderByData == NULL)
--- a/src/ivfutils.c
+++ b/src/ivfutils.c
@@ -1,19 +1,13 @@
 #include "postgres.h"

-#include "access/genam.h"
 #include "access/generic_xlog.h"
+#include "bitvec.h"
+#include "catalog/pg_type.h"
 #include "fmgr.h"
 #include "halfutils.h"
 #include "halfvec.h"
 #include "ivfflat.h"
 #include "storage/bufmgr.h"
-#include "utils/relcache.h"
-#include "utils/varbit.h"
-#include "vector.h"
-
-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif

 /*
 * Allocate a vector array
--- a/src/ivfvacuum.c
+++ b/src/ivfvacuum.c
@@ -1,12 +1,9 @@
 #include "postgres.h"

-#include "access/genam.h"
 #include "access/generic_xlog.h"
-#include "access/itup.h"
 #include "commands/vacuum.h"
 #include "ivfflat.h"
 #include "storage/bufmgr.h"
-#include "utils/relcache.h"

 #if PG_VERSION_NUM >= 180000
 #define vacuum_delay_point() vacuum_delay_point(false)
--- a/src/sparsevec.c
+++ b/src/sparsevec.c
@@ -5,27 +5,18 @@

 #include "catalog/pg_type.h"
 #include "common/shortest_dec.h"
+#include "common/string.h"
 #include "fmgr.h"
 #include "halfutils.h"
 #include "halfvec.h"
-#include "lib/stringinfo.h"
 #include "libpq/pqformat.h"
 #include "sparsevec.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/float.h"
-#include "utils/fmgrprotos.h"
 #include "utils/lsyscache.h"
 #include "vector.h"

-#if PG_VERSION_NUM >= 160000
-#include "varatt.h"
-#endif
-
-#if PG_VERSION_NUM >= 170000
-#include "parser/scansup.h"
-#endif
-
 typedef struct SparseInputElement
 {
 	int32		index;
@@ -159,9 +150,9 @@ InitSparseVector(int dim, int nnz)
 	return result;
 }

-#if PG_VERSION_NUM >= 170000
-#define sparsevec_isspace(ch) scanner_isspace(ch)
-#else
+/*
+ * Check for whitespace, since array_isspace() is static
+ */
 static inline bool
 sparsevec_isspace(char ch)
 {
@@ -174,7 +165,6 @@ sparsevec_isspace(char ch)
 		return true;
 	return false;
 }
-#endif

 /*
 * Compare indices
@@ -182,10 +172,10 @@ sparsevec_isspace(char ch)
 static int
 CompareIndices(const void *a, const void *b)
 {
-	if (((const SparseInputElement *) a)->index < ((const SparseInputElement *) b)->index)
+	if (((SparseInputElement *) a)->index < ((SparseInputElement *) b)->index)
 		return -1;

-	if (((const SparseInputElement *) a)->index > ((const SparseInputElement *) b)->index)
+	if (((SparseInputElement *) a)->index > ((SparseInputElement *) b)->index)
 		return 1;

 	return 0;
--- a/src/vector.c
+++ b/src/vector.c
@@ -16,20 +16,16 @@
 #include "port.h"				/* for strtof() */
 #include "sparsevec.h"
 #include "utils/array.h"
+#include "utils/builtins.h"
 #include "utils/float.h"
-#include "utils/fmgrprotos.h"
 #include "utils/lsyscache.h"
-#include "utils/varbit.h"
+#include "utils/numeric.h"
 #include "vector.h"

 #if PG_VERSION_NUM >= 160000
 #include "varatt.h"
 #endif

-#if PG_VERSION_NUM >= 170000
-#include "parser/scansup.h"
-#endif
-
 #define STATE_DIMS(x) (ARR_DIMS(x)[0] - 1)
 #define CreateStateDatums(dim) palloc(sizeof(Datum) * (dim + 1))

@@ -39,11 +35,7 @@
 #define VECTOR_TARGET_CLONES
 #endif

-#if PG_VERSION_NUM >= 180000
-PG_MODULE_MAGIC_EXT(.name = "vector", .version = "0.8.2");
-#else
 PG_MODULE_MAGIC;
-#endif

 /*
 * Initialize index options and variables
@@ -133,9 +125,9 @@ InitVector(int dim)
 	return result;
 }

-#if PG_VERSION_NUM >= 170000
-#define vector_isspace(ch) scanner_isspace(ch)
-#else
+/*
+ * Check for whitespace, since array_isspace() is static
+ */
 static inline bool
 vector_isspace(char ch)
 {
@@ -148,7 +140,6 @@ vector_isspace(char ch)
 		return true;
 	return false;
 }
-#endif

 /*
 * Check state array
@@ -925,17 +916,19 @@ vector_concat(PG_FUNCTION_ARGS)
 	Vector	   *b = PG_GETARG_VECTOR_P(1);
 	Vector	   *result;
 	int			dim = a->dim + b->dim;
+	int			dim_a = a->dim;
+	int			dim_b = b->dim;

 	CheckDim(dim);
 	result = InitVector(dim);

 	/* Auto-vectorized */
-	for (int i = 0, imax = a->dim; i < imax; i++)
+	for (int i = 0; i < dim_a; i++)
 		result->x[i] = a->x[i];

 	/* Auto-vectorized */
-	for (int i = 0, imax = b->dim, start = a->dim; i < imax; i++)
-		result->x[i + start] = b->x[i];
+	for (int i = 0; i < dim_b; i++)
+		result->x[i + dim_a] = b->x[i];

 	PG_RETURN_POINTER(result);
 }
@@ -951,21 +944,8 @@ binary_quantize(PG_FUNCTION_ARGS)
 	float	   *ax = a->x;
 	VarBit	   *result = InitBitVector(a->dim);
 	unsigned char *rx = VARBITS(result);
-	int			i = 0;
-	int			count = (a->dim / 8) * 8;

-	/* Auto-vectorized */
-	for (; i < count; i += 8)
-	{
-		unsigned char result_byte = 0;
-
-		for (int j = 0; j < 8; j++)
-			result_byte |= (ax[i + j] > 0) << (7 - j);
-
-		rx[i / 8] = result_byte;
-	}
-
-	for (; i < a->dim; i++)
+	for (int i = 0; i < a->dim; i++)
 		rx[i / 8] |= (ax[i] > 0) << (7 - (i % 8));

 	PG_RETURN_VARBIT_P(result);
--- a/test/expected/halfvec.out
+++ b/test/expected/halfvec.out
@@ -540,12 +540,6 @@ SELECT binary_quantize('[0,0.1,-0.2,-0.3,0.4,0.5,0.6,-0.7,0.8,-0.9,1]'::halfvec)
 01001110101
 (1 row)

-SELECT binary_quantize('[1,2,3,-4,5,6,-7,8,1,-2,-3,4,5,-6,7,8,-1,2,3]'::halfvec);
-   binary_quantize   
---------------------
- 1110110110011011011
-(1 row)
-
 SELECT subvector('[1,2,3,4,5]'::halfvec, 1, 3);
 subvector 
 -----------
--- a/test/expected/vector_type.out
+++ b/test/expected/vector_type.out
@@ -576,12 +576,6 @@ SELECT binary_quantize('[0,0.1,-0.2,-0.3,0.4,0.5,0.6,-0.7,0.8,-0.9,1]'::vector);
 01001110101
 (1 row)

-SELECT binary_quantize('[1,2,3,-4,5,6,-7,8,1,-2,-3,4,5,-6,7,8,-1,2,3]'::vector);
-   binary_quantize   
---------------------
- 1110110110011011011
-(1 row)
-
 SELECT subvector('[1,2,3,4,5]'::vector, 1, 3);
 subvector 
 -----------
--- a/test/sql/halfvec.sql
+++ b/test/sql/halfvec.sql
@@ -121,7 +121,6 @@ SELECT l2_normalize('[65504]'::halfvec);

 SELECT binary_quantize('[1,0,-1]'::halfvec);
 SELECT binary_quantize('[0,0.1,-0.2,-0.3,0.4,0.5,0.6,-0.7,0.8,-0.9,1]'::halfvec);
-SELECT binary_quantize('[1,2,3,-4,5,6,-7,8,1,-2,-3,4,5,-6,7,8,-1,2,3]'::halfvec);

 SELECT subvector('[1,2,3,4,5]'::halfvec, 1, 3);
 SELECT subvector('[1,2,3,4,5]'::halfvec, 3, 2);
--- a/test/sql/vector_type.sql
+++ b/test/sql/vector_type.sql
@@ -128,7 +128,6 @@ SELECT l2_normalize('[3e38]'::vector);

 SELECT binary_quantize('[1,0,-1]'::vector);
 SELECT binary_quantize('[0,0.1,-0.2,-0.3,0.4,0.5,0.6,-0.7,0.8,-0.9,1]'::vector);
-SELECT binary_quantize('[1,2,3,-4,5,6,-7,8,1,-2,-3,4,5,-6,7,8,-1,2,3]'::vector);

 SELECT subvector('[1,2,3,4,5]'::vector, 1, 3);
 SELECT subvector('[1,2,3,4,5]'::vector, 3, 2);
--- a/test/t/005_ivfflat_query_recall.pl
+++ b/test/t/005_ivfflat_query_recall.pl
@@ -16,19 +16,29 @@ $node->safe_psql("postgres",
 	"INSERT INTO tst SELECT i, ARRAY[random(), random(), random()] FROM generate_series(1, 100000) i;"
 );

-# Add index
-$node->safe_psql("postgres", "CREATE INDEX ON tst USING ivfflat (v vector_l2_ops);");
+# Check each index type
+my @operators = ("<->", "<#>", "<=>");
+my @opclasses = ("vector_l2_ops", "vector_ip_ops", "vector_cosine_ops");

-# Test 100% recall
-for (1 .. 20)
+for my $i (0 .. $#operators)
 {
-	my $id = int(rand() * 100000);
-	my $query = $node->safe_psql("postgres", "SELECT v FROM tst WHERE i = $id;");
-	my $res = $node->safe_psql("postgres", qq(
-		SET enable_seqscan = off;
-		SELECT v FROM tst ORDER BY v <-> '$query' LIMIT 1;
-	));
-	is($res, $query);
+	my $operator = $operators[$i];
+	my $opclass = $opclasses[$i];
+
+	# Add index
+	$node->safe_psql("postgres", "CREATE INDEX ON tst USING ivfflat (v $opclass);");
+
+	# Test 100% recall
+	for (1 .. 20)
+	{
+		my $id = int(rand() * 100000);
+		my $query = $node->safe_psql("postgres", "SELECT v FROM tst WHERE i = $id;");
+		my $res = $node->safe_psql("postgres", qq(
+			SET enable_seqscan = off;
+			SELECT v FROM tst ORDER BY v <-> '$query' LIMIT 1;
+		));
+		is($res, $query);
+	}
 }

 done_testing();
--- a/test/t/045_hnsw_low_memory_build.pl
+++ b/test/t/045_hnsw_low_memory_build.pl
@@ -1,29 +0,0 @@
-use strict;
-use warnings FATAL => 'all';
-use PostgreSQL::Test::Cluster;
-use PostgreSQL::Test::Utils;
-use Test::More;
-
-# Initialize node
-my $node = PostgreSQL::Test::Cluster->new('node');
-$node->init;
-$node->start;
-
-# Create table
-$node->safe_psql("postgres", "CREATE EXTENSION vector;");
-$node->safe_psql("postgres", "CREATE TABLE tst (v vector(3));");
-$node->safe_psql("postgres",
-	"INSERT INTO tst SELECT ARRAY[random(), random(), random()] FROM generate_series(1, 1000) i;"
-);
-
-my ($ret, $stdout, $stderr) = $node->psql("postgres", qq(
-	SET client_min_messages = DEBUG;
-	SET maintenance_work_mem = '3073kB';
-	ALTER TABLE tst SET (parallel_workers = 1);
-	CREATE INDEX ON tst USING hnsw (v vector_l2_ops);
-));
-is($ret, 0, $stderr);
-like($stderr, qr/using \d+ parallel workers/);
-like($stderr, qr/hnsw graph no longer fits into maintenance_work_mem after 0 tuples/);
-
-done_testing();
--- a/vector.control
+++ b/vector.control
@@ -1,4 +1,4 @@
 comment = 'vector data type and ivfflat and hnsw access methods'
-default_version = '0.8.2'
+default_version = '0.8.0'
 module_pathname = '$libdir/vector'
 relocatable = true
Author	SHA1	Message	Date
Andrew Kane	e2f915c46b	Use maintenance_io_concurrency where needed [skip ci]	2025-07-12 09:12:00 -07:00
Andrew Kane	6caa4ec207	Updated comment [skip ci]	2025-07-12 09:10:43 -07:00
Andrew Kane	b9b5e8d305	Fixed compiler warning [skip ci]	2025-07-12 08:58:07 -07:00
Andrew Kane	1c8128d2f0	Improved naming [skip ci]	2025-07-11 18:45:54 -07:00
Andrew Kane	e09d9f0abb	Added todo [skip ci]	2025-07-11 18:38:44 -07:00
Andrew Kane	f6e9a56415	Improved code [skip ci]	2025-07-11 17:11:39 -07:00
Andrew Kane	911935b695	Improved performance of HNSW index scans for Postgres 17	2025-07-11 16:36:17 -07:00