Try again

This reverts commit 94eeb83abe.

.editorconfig

@@ -1,6 +1,6 @@
 root = true
 
-[*.{c,h,pl}]
+[*.{c,h,pl,pm}]
 indent_style = tab
 indent_size = tab
 tab_width = 4

.github/workflows/build.yml

@@ -1,38 +1,65 @@
 name: build
 on: [push, pull_request]
 jobs:
-  build:
+  ubuntu:
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
+    if: ${{ !startsWith(github.ref_name, 'windows') }}
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest]
+        postgres: [15, 14, 13, 12, 11, 10]
-        postgres: [14, 13, 12, 11, 10, 9.6]
-        include:
-        - os: macos-latest
-          postgres: 14
     steps:
-    - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: ankane/setup-postgres@v1
         with:
           postgres-version: ${{ matrix.postgres }}
-    - if: ${{ startsWith(matrix.os, 'ubuntu') }}
+          dev-files: true
-      run: sudo apt-get update && sudo apt-get install postgresql-server-dev-${{ matrix.postgres }} libipc-run-perl
       - run: make
-    - if: ${{ startsWith(matrix.os, 'ubuntu') }}
+      - run: |
-      run: |
           export PG_CONFIG=`which pg_config`
           sudo --preserve-env=PG_CONFIG make install
-    - if: ${{ startsWith(matrix.os, 'macos') }}
-      run: make install
       - run: make installcheck
       - if: ${{ failure() }}
         run: cat regression.diffs
-    - if: ${{ startsWith(matrix.os, 'ubuntu') }}
+      - run: |
-      run: make prove_installcheck
+          sudo apt-get update
-    - if: ${{ startsWith(matrix.os, 'macos') }}
+          sudo apt-get install libipc-run-perl
-      run: |
+          make prove_installcheck
-        brew install cpanm && cpanm IPC::Run
+  mac:
-        wget -q https://github.com/postgres/postgres/archive/refs/tags/REL_14_1.tar.gz
+    runs-on: macos-latest
-        tar xf REL_14_1.tar.gz
+    if: ${{ !startsWith(github.ref_name, 'windows') }}
-        make prove_installcheck PROVE=prove PERL5LIB=postgres-REL_14_1/src/test/perl
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ankane/setup-postgres@v1
+        with:
+          postgres-version: 14
+      - run: make
+      - run: make install
+      - run: make installcheck
+      - if: ${{ failure() }}
+        run: cat regression.diffs
+      - run: |
+          brew install cpanm
+          cpanm IPC::Run
+          wget -q https://github.com/postgres/postgres/archive/refs/tags/REL_14_5.tar.gz
+          tar xf REL_14_5.tar.gz
+          make prove_installcheck PROVE=prove PROVE_FLAGS="-I ./postgres-REL_14_5/src/test/perl" PERL5LIB="/Users/runner/perl5/lib/perl5"
+  windows:
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ankane/setup-postgres@v1
+        with:
+          postgres-version: 14
+      - run: |
+          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
+          curl -Ls -o REL_14_5.tar.gz https://github.com/postgres/postgres/archive/refs/tags/REL_14_5.tar.gz
+          7z x REL_14_5.tar.gz
+          7z x REL_14_5.tar
+          ls ./postgres-REL_14_5/src/test/perl
+          set PROVE=prove
+          set PROVE_FLAGS="-I ./postgres-REL_14_5/src/test/perl"
+          nmake /NOLOGO /F Makefile.win prove_installcheck
+        shell: cmd

.gitignore

@@ -5,3 +5,4 @@
 regression.*
 *.o
 *.so
+*.bc

CHANGELOG.md

@@ -1,6 +1,31 @@
-## 0.2.6 (unreleased)
+## 0.4.0 (unreleased)
+
+- Changed text representation for vector elements to match `real`
+- Improved accuracy of text parsing for certain inputs
+- Added experimental support for Windows
+
+## 0.3.2 (2022-11-22)
+
+- Fixed `invalid memory alloc request size` error
+
+## 0.3.1 (2022-11-02)
+
+If upgrading from 0.2.7 or 0.3.0, [recreate](https://github.com/pgvector/pgvector#031) all `ivfflat` indexes after upgrading to ensure all data is indexed.
+
+- Fixed issue with inserts silently corrupting `ivfflat` indexes (introduced in 0.2.7)
+- Fixed segmentation fault with index creation when lists > 6500
+
+## 0.3.0 (2022-10-15)
+
+- Added support for Postgres 15
+- Dropped support for Postgres 9.6
+
+## 0.2.7 (2022-07-31)
+
+- Fixed `unexpected data beyond EOF` error
+
+## 0.2.6 (2022-05-22)
 
-- Switched to mini-batch k-means
 - Improved performance of index creation for Postgres < 12
 
 ## 0.2.5 (2022-02-11)

Dockerfile

@@ -1,9 +1,9 @@
-FROM postgres:14
+FROM postgres:15
 
 COPY . /tmp/pgvector
 
 RUN apt-get update && \
-		apt-get install -y --no-install-recommends build-essential postgresql-server-dev-14 && \
+		apt-get install -y --no-install-recommends build-essential postgresql-server-dev-15 && \
 		cd /tmp/pgvector && \
 		make clean && \
 		make OPTFLAGS="" && \
@@ -11,6 +11,6 @@ RUN apt-get update && \
 		mkdir /usr/share/doc/pgvector && \
 		cp LICENSE README.md /usr/share/doc/pgvector && \
 		rm -r /tmp/pgvector && \
-		apt-get remove -y build-essential postgresql-server-dev-14 && \
+		apt-get remove -y build-essential postgresql-server-dev-15 && \
 		apt-get autoremove -y && \
 		rm -rf /var/lib/apt/lists/*

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": "0.2.5",
+	"version": "0.3.2",
 	"maintainer": [
 		"Andrew Kane <andrew@ankane.org>"
 	],
@@ -12,7 +12,7 @@
 	"prereqs": {
 		"runtime": {
 			"requires": {
-				"PostgreSQL": "9.6.0"
+				"PostgreSQL": "10.0.0"
 			}
 		}
 	},
@@ -20,7 +20,7 @@
 		"vector": {
 			"file": "sql/vector.sql",
 			"docfile": "README.md",
-			"version": "0.2.5",
+			"version": "0.3.2",
 			"abstract": "Open-source vector similarity search for Postgres"
 		}
 	},

Makefile

@@ -1,5 +1,5 @@
 EXTENSION = vector
-EXTVERSION = 0.2.5
+EXTVERSION = 0.3.2
 
 MODULE_big = vector
 DATA = $(wildcard sql/*--*.sql)
@@ -7,7 +7,7 @@ OBJS = src/ivfbuild.o src/ivfflat.o src/ivfinsert.o src/ivfkmeans.o src/ivfscan.
 
 TESTS = $(wildcard test/sql/*.sql)
 REGRESS = $(patsubst test/sql/%.sql,%,$(TESTS))
-REGRESS_OPTS = --inputdir=test
+REGRESS_OPTS = --inputdir=test --load-extension=vector
 
 OPTFLAGS = -march=native
 
@@ -40,6 +40,9 @@ PG_CONFIG ?= pg_config
 PGXS := $(shell $(PG_CONFIG) --pgxs)
 include $(PGXS)
 
+# for Postgres 15
+PROVE_FLAGS += -I ./test/perl
+
 prove_installcheck:
 	rm -rf $(CURDIR)/tmp_check
 	cd $(srcdir) && TESTDIR='$(CURDIR)' PATH="$(bindir):$$PATH" PGPORT='6$(DEF_PGPORT)' PG_REGRESS='$(top_builddir)/src/test/regress/pg_regress' $(PROVE) $(PG_PROVE_FLAGS) $(PROVE_FLAGS) $(if $(PROVE_TESTS),$(PROVE_TESTS),test/t/*.pl)

Makefile.win

@@ -0,0 +1,62 @@
+EXTENSION = vector
+EXTVERSION = 0.3.2
+
+OBJS = src\ivfbuild.obj src\ivfflat.obj src\ivfinsert.obj src\ivfkmeans.obj src\ivfscan.obj src\ivfutils.obj src\ivfvacuum.obj src\vector.obj
+
+REGRESS = btree cast copy functions input ivfflat_cosine ivfflat_ip ivfflat_l2 ivfflat_options ivfflat_unlogged
+REGRESS_OPTS = --inputdir=test --load-extension=vector
+
+# For /arch flags
+# https://learn.microsoft.com/en-us/cpp/build/reference/arch-minimum-cpu-architecture
+OPTFLAGS =
+
+# For auto-vectorization:
+# - MSVC (needs /O2 /fp:fast) - https://learn.microsoft.com/en-us/cpp/parallel/auto-parallelization-and-auto-vectorization?#auto-vectorizer
+PG_CFLAGS = $(PG_CFLAGS) $(OPTFLAGS) /O2 /fp:fast
+
+# Debug MSVC auto-vectorization
+# https://learn.microsoft.com/en-us/cpp/error-messages/tool-errors/vectorizer-and-parallelizer-messages
+# PG_CFLAGS = $(PG_CFLAGS) /Qvec-report:2
+
+all: sql\$(EXTENSION)--$(EXTVERSION).sql
+
+sql\$(EXTENSION)--$(EXTVERSION).sql: sql\$(EXTENSION).sql
+	copy sql\$(EXTENSION).sql $@
+
+# TODO use pg_config
+BINDIR = $(PGROOT)\bin
+INCLUDEDIR = $(PGROOT)\include
+INCLUDEDIR_SERVER = $(PGROOT)\include\server
+LIBDIR = $(PGROOT)\lib
+PKGLIBDIR = $(PGROOT)\lib
+SHAREDIR = $(PGROOT)\share
+
+CFLAGS = /nologo /I"$(INCLUDEDIR_SERVER)\port\win32_msvc" /I"$(INCLUDEDIR_SERVER)\port\win32" /I"$(INCLUDEDIR_SERVER)" /I"$(INCLUDEDIR)"
+
+CFLAGS = $(CFLAGS) $(PG_CFLAGS)
+
+SHLIB = src\$(EXTENSION).dll
+
+LIBS = "$(LIBDIR)\postgres.lib"
+
+.c.obj:
+	$(CC) $(CFLAGS) /c $< /Fo$@
+
+$(SHLIB): $(OBJS)
+	$(CC) $(CFLAGS) $(OBJS) $(LIBS) /link /DLL /OUT:$(SHLIB)
+
+all: $(SHLIB)
+
+install:
+	copy $(SHLIB) "$(PKGLIBDIR)"
+	copy $(EXTENSION).control "$(SHAREDIR)\extension"
+	copy sql\$(EXTENSION)--*.sql "$(SHAREDIR)\extension"
+
+installcheck:
+	"$(BINDIR)\pg_regress" --bindir="$(BINDIR)" $(REGRESS_OPTS) $(REGRESS)
+
+prove_installcheck:
+	rm -rf tmp_check
+	set PGPORT=65432
+	set PG_REGRESS="$(BINDIR)\pg_regress"
+	$(PROVE) $(PG_PROVE_FLAGS) $(PROVE_FLAGS) test/t/*.pl

README.md

@@ -3,9 +3,9 @@
 Open-source vector similarity search for Postgres
 
 ```sql
-CREATE TABLE table (column vector(3));
+CREATE TABLE items (embedding vector(3));
-CREATE INDEX ON table USING ivfflat (column vector_l2_ops);
+CREATE INDEX ON items USING ivfflat (embedding vector_l2_ops);
-SELECT * FROM table ORDER BY column <-> '[1,2,3]' LIMIT 5;
+SELECT * FROM items ORDER BY embedding <-> '[1,2,3]' LIMIT 5;
 ```
 
 Supports L2 distance, inner product, and cosine distance
@@ -14,10 +14,10 @@ Supports L2 distance, inner product, and cosine distance
 
 ## Installation
 
-Compile and install the extension (supports Postgres 9.6+)
+Compile and install the extension (supports Postgres 10+)
 
 ```sh
-git clone --branch v0.2.5 https://github.com/pgvector/pgvector.git
+git clone --branch v0.3.2 https://github.com/pgvector/pgvector.git
 cd pgvector
 make
 make install # may need sudo
@@ -33,22 +33,22 @@ You can also install it with [Docker](#docker), [Homebrew](#homebrew), or [PGXN]
 
 ## Getting Started
 
-Create a vector column with 3 dimensions (replace `table` and `column` with non-reserved names)
+Create a vector column with 3 dimensions
 
 ```sql
-CREATE TABLE table (column vector(3));
+CREATE TABLE items (embedding vector(3));
 ```
 
 Insert values
 
 ```sql
-INSERT INTO table VALUES ('[1,2,3]'), ('[4,5,6]');
+INSERT INTO items VALUES ('[1,2,3]'), ('[4,5,6]');
 ```
 
 Get the nearest neighbor by L2 distance
 
 ```sql
-SELECT * FROM table ORDER BY column <-> '[3,1,2]' LIMIT 1;
+SELECT * FROM items ORDER BY embedding <-> '[3,1,2]' LIMIT 1;
 ```
 
 Also supports inner product (`<#>`) and cosine distance (`<=>`)
@@ -62,19 +62,19 @@ Speed up queries with an approximate index. Add an index for each distance funct
 L2 distance
 
 ```sql
-CREATE INDEX ON table USING ivfflat (column vector_l2_ops);
+CREATE INDEX ON items USING ivfflat (embedding vector_l2_ops);
 ```
 
 Inner product
 
 ```sql
-CREATE INDEX ON table USING ivfflat (column vector_ip_ops);
+CREATE INDEX ON items USING ivfflat (embedding vector_ip_ops);
 ```
 
 Cosine distance
 
 ```sql
-CREATE INDEX ON table USING ivfflat (column vector_cosine_ops);
+CREATE INDEX ON items USING ivfflat (embedding vector_cosine_ops);
 ```
 
 Indexes should be created after the table has some data for optimal clustering. Also, unlike typical indexes which only affect performance, you may see different results for queries after adding an approximate index.
@@ -84,7 +84,7 @@ Indexes should be created after the table has some data for optimal clustering.
 Specify the number of inverted lists (100 by default)
 
 ```sql
-CREATE INDEX ON table USING ivfflat (column opclass) WITH (lists = 100);
+CREATE INDEX ON items USING ivfflat (embedding vector_l2_ops) WITH (lists = 100);
 ```
 
 A [good place to start](https://github.com/facebookresearch/faiss/issues/112) is `4 * sqrt(rows)`
@@ -119,9 +119,10 @@ SELECT phase, tuples_done, tuples_total FROM pg_stat_progress_create_index;
 The phases are:
 
 1. `initializing`
-2. `performing k-means`
+2. `sampling table`
-3. `sorting tuples`
+3. `performing k-means`
-4. `loading tuples`
+4. `sorting tuples`
+5. `loading tuples`
 
 Note: `tuples_done` and `tuples_total` are only populated during the `loading tuples` phase
 
@@ -130,10 +131,20 @@ Note: `tuples_done` and `tuples_total` are only populated during the `loading tu
 Consider [partial indexes](https://www.postgresql.org/docs/current/indexes-partial.html) for queries with a `WHERE` clause
 
 ```sql
-CREATE INDEX ON table USING ivfflat (column opclass) WHERE (other_column = 123);
+SELECT * FROM items WHERE category_id = 123 ORDER BY embedding <-> '[3,1,2]' LIMIT 5;
 ```
 
-To index many different values of `other_column`, consider [partitioning](https://www.postgresql.org/docs/current/ddl-partitioning.html) on `other_column`.
+can be indexed with:
+
+```sql
+CREATE INDEX ON items USING ivfflat (embedding vector_l2_ops) WHERE (category_id = 123);
+```
+
+To index many different values of `category_id`, consider [partitioning](https://www.postgresql.org/docs/current/ddl-partitioning.html) on `category_id`.
+
+```sql
+CREATE TABLE items (embedding vector(3), category_id int) PARTITION BY LIST(category_id);
+```
 
 ## Performance
 
@@ -146,14 +157,14 @@ SET max_parallel_workers_per_gather = 4;
 To speed up queries with an index, increase the number of inverted lists (at the expense of recall).
 
 ```sql
-CREATE INDEX ON table USING ivfflat (column opclass) WITH (lists = 1000);
+CREATE INDEX ON items USING ivfflat (embedding vector_l2_ops) WITH (lists = 1000);
 ```
 
 ## Reference
 
 ### Vector Type
 
-Each vector takes `4 * dimensions + 8` bytes of storage. Each element is a float, and all elements must be finite (no `NaN`, `Infinity` or `-Infinity`). Vectors can have up to 1024 dimensions.
+Each vector takes `4 * dimensions + 8` bytes of storage. Each element is a single precision floating-point number (like the `real` type in Postgres), and all elements must be finite (no `NaN`, `Infinity` or `-Infinity`). Vectors can have up to 1024 dimensions.
 
 ### Vector Operators
 
@@ -184,8 +195,10 @@ Libraries that use pgvector:
 - [pgvector-ruby](https://github.com/pgvector/pgvector-ruby) (Ruby)
 - [pgvector-node](https://github.com/pgvector/pgvector-node) (Node.js)
 - [pgvector-go](https://github.com/pgvector/pgvector-go) (Go)
+- [pgvector-php](https://github.com/pgvector/pgvector-php) (PHP)
 - [pgvector-rust](https://github.com/pgvector/pgvector-rust) (Rust)
 - [pgvector-cpp](https://github.com/pgvector/pgvector-cpp) (C++)
+- [pgvector-elixir](https://github.com/pgvector/pgvector-elixir) (Elixir)
 
 ## Frequently Asked Questions
 
@@ -219,14 +232,14 @@ This adds pgvector to the [Postgres image](https://hub.docker.com/_/postgres).
 You can also build the image manually
 
 ```sh
-git clone --branch v0.2.5 https://github.com/pgvector/pgvector.git
+git clone --branch v0.3.2 https://github.com/pgvector/pgvector.git
 cd pgvector
 docker build -t pgvector .
 ```
 
 ### Homebrew
 
-On Mac with Homebrew Postgres, you can use:
+With Homebrew Postgres, you can use:
 
 ```sh
 brew install pgvector/brew/pgvector
@@ -257,13 +270,29 @@ Install the latest version and run:
 ALTER EXTENSION vector UPDATE;
 ```
 
+## Upgrade Notes
+
+### 0.3.1
+
+If upgrading from 0.2.7 or 0.3.0, recreate all `ivfflat` indexes after upgrading to ensure all data is indexed.
+
+```sql
+-- Postgres 12+
+REINDEX INDEX CONCURRENTLY index_name;
+
+-- Postgres < 12
+CREATE INDEX CONCURRENTLY temp_name ON table USING ivfflat (column opclass);
+DROP INDEX CONCURRENTLY index_name;
+ALTER INDEX temp_name RENAME TO index_name;
+```
+
 ## Thanks
 
 Thanks to:
 
 - [PASE: PostgreSQL Ultra-High-Dimensional Approximate Nearest Neighbor Search Extension](https://dl.acm.org/doi/pdf/10.1145/3318464.3386131)
 - [Faiss: A Library for Efficient Similarity Search and Clustering of Dense Vectors](https://github.com/facebookresearch/faiss)
-- [Web-Scale k-means Clustering](https://www.eecs.tufts.edu/~dsculley/papers/fastkmeans.pdf)
+- [Using the Triangle Inequality to Accelerate k-means](https://www.aaai.org/Papers/ICML/2003/ICML03-022.pdf)
 - [k-means++: The Advantage of Careful Seeding](https://theory.stanford.edu/~sergei/papers/kMeansPP-soda.pdf)
 - [Concept Decompositions for Large Sparse Text Data using Clustering](https://www.cs.utexas.edu/users/inderjit/public_papers/concept_mlj.pdf)
 

sql/vector--0.2.5--0.2.6.sql

@@ -0,0 +1,2 @@
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION vector UPDATE TO '0.2.6'" to load this file. \quit

sql/vector--0.2.6--0.2.7.sql

@@ -0,0 +1,2 @@
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION vector UPDATE TO '0.2.7'" to load this file. \quit

sql/vector--0.2.7--0.3.0.sql

@@ -0,0 +1,2 @@
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION vector UPDATE TO '0.3.0'" to load this file. \quit

sql/vector--0.3.0--0.3.1.sql

@@ -0,0 +1,2 @@
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION vector UPDATE TO '0.3.1'" to load this file. \quit

sql/vector--0.3.1--0.3.2.sql

@@ -0,0 +1,2 @@
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION vector UPDATE TO '0.3.2'" to load this file. \quit

src/ivfbuild.c

@@ -42,6 +42,91 @@
 #define UpdateProgress(index, val) ((void)val)
 #endif
 
+/*
+ * Callback for sampling
+ */
+static void
+SampleCallback(Relation index, CALLBACK_ITEM_POINTER, Datum *values,
+			   bool *isnull, bool tupleIsAlive, void *state)
+{
+	IvfflatBuildState *buildstate = (IvfflatBuildState *) state;
+	VectorArray samples = buildstate->samples;
+	int			targsamples = samples->maxlen;
+	Datum		value = values[0];
+
+	/* Skip nulls */
+	if (isnull[0])
+		return;
+
+	/*
+	 * Normalize with KMEANS_NORM_PROC since spherical distance function
+	 * expects unit vectors
+	 */
+	if (buildstate->kmeansnormprocinfo != NULL)
+	{
+		if (!IvfflatNormValue(buildstate->kmeansnormprocinfo, buildstate->collation, &value, buildstate->normvec))
+			return;
+	}
+
+	if (samples->length < targsamples)
+	{
+		VectorArraySet(samples, samples->length, DatumGetVector(value));
+		samples->length++;
+	}
+	else
+	{
+		if (buildstate->rowstoskip < 0)
+			buildstate->rowstoskip = reservoir_get_next_S(&buildstate->rstate, samples->length, targsamples);
+
+		if (buildstate->rowstoskip <= 0)
+		{
+#if PG_VERSION_NUM >= 150000
+			int			k = (int) (targsamples * sampler_random_fract(&buildstate->rstate.randstate));
+#else
+			int			k = (int) (targsamples * sampler_random_fract(buildstate->rstate.randstate));
+#endif
+
+			Assert(k >= 0 && k < targsamples);
+			VectorArraySet(samples, k, DatumGetVector(value));
+		}
+
+		buildstate->rowstoskip -= 1;
+	}
+}
+
+/*
+ * Sample rows with same logic as ANALYZE
+ */
+static void
+SampleRows(IvfflatBuildState * buildstate)
+{
+	int			targsamples = buildstate->samples->maxlen;
+	BlockNumber totalblocks = RelationGetNumberOfBlocks(buildstate->heap);
+
+	UpdateProgress(PROGRESS_CREATEIDX_SUBPHASE, PROGRESS_IVFFLAT_PHASE_SAMPLE);
+
+	buildstate->rowstoskip = -1;
+
+	BlockSampler_Init(&buildstate->bs, totalblocks, targsamples, RandomInt());
+
+	reservoir_init_selection_state(&buildstate->rstate, targsamples);
+	while (BlockSampler_HasMore(&buildstate->bs))
+	{
+		BlockNumber targblock = BlockSampler_Next(&buildstate->bs);
+
+#if PG_VERSION_NUM >= 120000
+		table_index_build_range_scan(buildstate->heap, buildstate->index, buildstate->indexInfo,
+									 false, true, false, targblock, 1, SampleCallback, (void *) buildstate, NULL);
+#elif PG_VERSION_NUM >= 110000
+		IndexBuildHeapRangeScan(buildstate->heap, buildstate->index, buildstate->indexInfo,
+								false, true, targblock, 1, SampleCallback, (void *) buildstate, NULL);
+#else
+		IndexBuildHeapRangeScan(buildstate->heap, buildstate->index, buildstate->indexInfo,
+								false, true, targblock, 1, SampleCallback, (void *) buildstate);
+#endif
+	}
+}
+
 /*
  * Callback for table_index_build_scan
  */
@@ -148,8 +233,8 @@ InsertTuples(Relation index, IvfflatBuildState * buildstate, ForkNumber forkNum)
 	GenericXLogState *state;
 	int			list;
 	IndexTuple	itup = NULL;	/* silence compiler warning */
-	BlockNumber startPage = InvalidBlockNumber;
+	BlockNumber startPage;
-	BlockNumber insertPage = InvalidBlockNumber;
+	BlockNumber insertPage;
 	Size		itemsz;
 	int			i;
 	int64		inserted = 0;
@@ -174,7 +259,7 @@ InsertTuples(Relation index, IvfflatBuildState * buildstate, ForkNumber forkNum)
 		CHECK_FOR_INTERRUPTS();
 
 		buf = IvfflatNewBuffer(index, forkNum);
-		IvfflatInitPage(index, &buf, &page, &state);
+		IvfflatInitRegisterPage(index, &buf, &page, &state);
 
 		startPage = BufferGetBlockNumber(buf);
 
@@ -277,7 +362,7 @@ InitBuildState(IvfflatBuildState * buildstate, Relation heap, Relation index, In
 static void
 FreeBuildState(IvfflatBuildState * buildstate)
 {
-	pfree(buildstate->centers);
+	VectorArrayFree(buildstate->centers);
 	pfree(buildstate->listInfo);
 	pfree(buildstate->normvec);
 
@@ -287,6 +372,38 @@ FreeBuildState(IvfflatBuildState * buildstate)
 #endif
 }
 
+/*
+ * Compute centers
+ */
+static void
+ComputeCenters(IvfflatBuildState * buildstate)
+{
+	int			numSamples;
+
+	/* Target 50 samples per list, with at least 10000 samples */
+	/* The number of samples has a large effect on index build time */
+	numSamples = buildstate->lists * 50;
+	if (numSamples < 10000)
+		numSamples = 10000;
+
+	/* Skip samples for unlogged table */
+	if (buildstate->heap == NULL)
+		numSamples = 1;
+
+	/* Sample rows */
+	/* TODO Ensure within maintenance_work_mem */
+	buildstate->samples = VectorArrayInit(numSamples, buildstate->dimensions);
+	if (buildstate->heap != NULL)
+		SampleRows(buildstate);
+
+	/* Calculate centers */
+	UpdateProgress(PROGRESS_CREATEIDX_SUBPHASE, PROGRESS_IVFFLAT_PHASE_KMEANS);
+	IvfflatBench("k-means", IvfflatKmeans(buildstate->index, buildstate->samples, buildstate->centers));
+
+	/* Free samples before we allocate more memory */
+	VectorArrayFree(buildstate->samples);
+}
+
 /*
  * Create the metapage
  */
@@ -299,7 +416,7 @@ CreateMetaPage(Relation index, int dimensions, int lists, ForkNumber forkNum)
 	IvfflatMetaPage metap;
 
 	buf = IvfflatNewBuffer(index, forkNum);
-	IvfflatInitPage(index, &buf, &page, &state);
+	IvfflatInitRegisterPage(index, &buf, &page, &state);
 
 	/* Set metapage data */
 	metap = IvfflatPageGetMeta(page);
@@ -332,7 +449,7 @@ CreateListPages(Relation index, VectorArray centers, int dimensions,
 	list = palloc(itemsz);
 
 	buf = IvfflatNewBuffer(index, forkNum);
-	IvfflatInitPage(index, &buf, &page, &state);
+	IvfflatInitRegisterPage(index, &buf, &page, &state);
 
 	for (i = 0; i < lists; i++)
 	{
@@ -460,9 +577,7 @@ BuildIndex(Relation heap, Relation index, IndexInfo *indexInfo,
 {
 	InitBuildState(buildstate, heap, index, indexInfo);
 
-	/* Perform k-means clustering */
+	ComputeCenters(buildstate);
-	UpdateProgress(PROGRESS_CREATEIDX_SUBPHASE, PROGRESS_IVFFLAT_PHASE_KMEANS);
-	IvfflatBench("k-means", IvfflatKmeans(buildstate));
 
 	/* Create pages */
 	CreateMetaPage(index, buildstate->dimensions, buildstate->lists, forkNum);

src/ivfflat.c

@@ -45,6 +45,8 @@ ivfflatbuildphasename(int64 phasenum)
 	{
 		case PROGRESS_CREATEIDX_SUBPHASE_INITIALIZE:
 			return "initializing";
+		case PROGRESS_IVFFLAT_PHASE_SAMPLE:
+			return "sampling table";
 		case PROGRESS_IVFFLAT_PHASE_KMEANS:
 			return "performing k-means";
 		case PROGRESS_IVFFLAT_PHASE_SORT:
@@ -162,7 +164,7 @@ ivfflatvalidate(Oid opclassoid)
  *
  * See https://www.postgresql.org/docs/current/index-api.html
  */
-PG_FUNCTION_INFO_V1(ivfflathandler);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(ivfflathandler);
 Datum
 ivfflathandler(PG_FUNCTION_ARGS)
 {

src/ivfflat.h

@@ -3,19 +3,24 @@
 
 #include "postgres.h"
 
+#if PG_VERSION_NUM < 100000
+#error "Requires PostgreSQL 10+"
+#endif
+
 #include "access/generic_xlog.h"
 #include "access/reloptions.h"
 #include "nodes/execnodes.h"
+#include "port.h"				/* for strtof() and random() */
 #include "utils/sampling.h"
 #include "utils/tuplesort.h"
 #include "vector.h"
 
-#ifdef IVFFLAT_BENCH
+#if PG_VERSION_NUM >= 150000
-#include "portability/instr_time.h"
+#include "common/pg_prng.h"
 #endif
 
-#if PG_VERSION_NUM < 90600
+#ifdef IVFFLAT_BENCH
-#error "Requires PostgreSQL 9.6+"
+#include "portability/instr_time.h"
 #endif
 
 /* Support functions */
@@ -37,9 +42,10 @@
 
 /* Build phases */
 /* PROGRESS_CREATEIDX_SUBPHASE_INITIALIZE is 1 */
-#define PROGRESS_IVFFLAT_PHASE_KMEANS	2
+#define PROGRESS_IVFFLAT_PHASE_SAMPLE	2
-#define PROGRESS_IVFFLAT_PHASE_SORT		3
+#define PROGRESS_IVFFLAT_PHASE_KMEANS	3
-#define PROGRESS_IVFFLAT_PHASE_LOAD		4
+#define PROGRESS_IVFFLAT_PHASE_SORT		4
+#define PROGRESS_IVFFLAT_PHASE_LOAD		5
 
 #define IVFFLAT_LIST_SIZE(_dim)	(offsetof(IvfflatListData, center) + VECTOR_SIZE(_dim))
 
@@ -61,15 +67,26 @@
 #define IvfflatBench(name, code) (code)
 #endif
 
+#if PG_VERSION_NUM >= 150000
+#define RandomDouble() pg_prng_double(&pg_global_prng_state)
+#define RandomInt() pg_prng_uint32(&pg_global_prng_state)
+#else
+#define RandomDouble() (((double) random()) / MAX_RANDOM_VALUE)
+#define RandomInt() random()
+#endif
+
 /* Variables */
 extern int	ivfflat_probes;
 
+/* Exported functions */
+PGDLLEXPORT void _PG_init(void);
+
 typedef struct VectorArrayData
 {
 	int			length;
 	int			maxlen;
 	int			dim;
-	Vector		items[FLEXIBLE_ARRAY_MEMBER];
+	Vector	   *items;
 }			VectorArrayData;
 
 typedef VectorArrayData * VectorArray;
@@ -190,16 +207,16 @@ typedef struct IvfflatScanOpaqueData
 
 typedef IvfflatScanOpaqueData * IvfflatScanOpaque;
 
-#define VECTOR_ARRAY_SIZE(_length, _dim) (offsetof(VectorArrayData, items) + _length * VECTOR_SIZE(_dim))
+#define VECTOR_ARRAY_SIZE(_length, _dim) (sizeof(VectorArrayData) + (_length) * VECTOR_SIZE(_dim))
-#define VECTOR_ARRAY_OFFSET(_arr, _offset) ((char*) _arr + offsetof(VectorArrayData, items) + (_offset) * VECTOR_SIZE(_arr->dim))
+#define VECTOR_ARRAY_OFFSET(_arr, _offset) ((char*) (_arr)->items + (_offset) * VECTOR_SIZE((_arr)->dim))
 #define VectorArrayGet(_arr, _offset) ((Vector *) VECTOR_ARRAY_OFFSET(_arr, _offset))
-#define VectorArraySet(_arr, _offset, _val) (memcpy(VECTOR_ARRAY_OFFSET(_arr, _offset), _val, VECTOR_SIZE(_arr->dim)))
+#define VectorArraySet(_arr, _offset, _val) memcpy(VECTOR_ARRAY_OFFSET(_arr, _offset), _val, VECTOR_SIZE((_arr)->dim))
 
 /* Methods */
-void		_PG_init(void);
 VectorArray VectorArrayInit(int maxlen, int dimensions);
+void		VectorArrayFree(VectorArray arr);
 void		PrintVectorArray(char *msg, VectorArray arr);
-void		IvfflatKmeans(IvfflatBuildState * buildstate);
+void		IvfflatKmeans(Relation index, VectorArray samples, VectorArray centers);
 FmgrInfo   *IvfflatOptionalProcInfo(Relation rel, uint16 procnum);
 bool		IvfflatNormValue(FmgrInfo *procinfo, Oid collation, Datum *value, Vector * result);
 int			IvfflatGetLists(Relation index);
@@ -207,7 +224,8 @@ void		IvfflatUpdateList(Relation index, GenericXLogState *state, ListInfo listIn
 void		IvfflatCommitBuffer(Buffer buf, GenericXLogState *state);
 void		IvfflatAppendPage(Relation index, Buffer *buf, Page *page, GenericXLogState **state, ForkNumber forkNum);
 Buffer		IvfflatNewBuffer(Relation index, ForkNumber forkNum);
-void		IvfflatInitPage(Relation index, Buffer *buf, Page *page, GenericXLogState **state);
+void		IvfflatInitPage(Buffer buf, Page page);
+void		IvfflatInitRegisterPage(Relation index, Buffer *buf, Page *page, GenericXLogState **state);
 
 /* Index access methods */
 IndexBuildResult *ivfflatbuild(Relation heap, Relation index, IndexInfo *indexInfo);

src/ivfinsert.c

@@ -53,18 +53,6 @@ FindInsertPage(Relation rel, Datum *values, BlockNumber *insertPage, ListInfo *
 	}
 }
 
-/*
- * Prepare to insert an index tuple
- */
-static void
-LoadInsertPage(Relation index, Buffer *buf, Page *page, GenericXLogState **state, BlockNumber insertPage)
-{
-	*buf = ReadBuffer(index, insertPage);
-	LockBuffer(*buf, BUFFER_LOCK_EXCLUSIVE);
-	*state = GenericXLogStart(index);
-	*page = GenericXLogRegisterBuffer(*state, *buf, 0);
-}
-
 /*
  * Insert a tuple into the index
  */
@@ -87,11 +75,18 @@ InsertTuple(Relation rel, IndexTuple itup, Relation heapRel, Datum *values)
 	itemsz = MAXALIGN(IndexTupleSize(itup));
 	Assert(itemsz <= BLCKSZ - MAXALIGN(SizeOfPageHeaderData) - MAXALIGN(sizeof(IvfflatPageOpaqueData)));
 
-	LoadInsertPage(rel, &buf, &page, &state, insertPage);
-
 	/* Find a page to insert the item */
-	while (PageGetFreeSpace(page) < itemsz)
+	for (;;)
 	{
+		buf = ReadBuffer(rel, insertPage);
+		LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
+
+		state = GenericXLogStart(rel);
+		page = GenericXLogRegisterBuffer(state, buf, 0);
+
+		if (PageGetFreeSpace(page) >= itemsz)
+			break;
+
 		insertPage = IvfflatPageGetOpaque(page)->nextblkno;
 
 		if (BlockNumberIsValid(insertPage))
@@ -99,15 +94,45 @@ InsertTuple(Relation rel, IndexTuple itup, Relation heapRel, Datum *values)
 			/* Move to next page */
 			GenericXLogAbort(state);
 			UnlockReleaseBuffer(buf);
-
-			LoadInsertPage(rel, &buf, &page, &state, insertPage);
 		}
 		else
 		{
-			/* Add a new page */
+			Buffer		metabuf;
-			IvfflatAppendPage(rel, &buf, &page, &state, MAIN_FORKNUM);
+			Buffer		newbuf;
+			Page		newpage;
 
-			insertPage = BufferGetBlockNumber(buf);
+			/*
+			 * From ReadBufferExtended: Caller is responsible for ensuring
+			 * that only one backend tries to extend a relation at the same
+			 * time!
+			 */
+			metabuf = ReadBuffer(rel, IVFFLAT_METAPAGE_BLKNO);
+			LockBuffer(metabuf, BUFFER_LOCK_EXCLUSIVE);
+
+			/* Add a new page */
+			newbuf = IvfflatNewBuffer(rel, MAIN_FORKNUM);
+			newpage = GenericXLogRegisterBuffer(state, newbuf, GENERIC_XLOG_FULL_IMAGE);
+
+			/* Init new page */
+			IvfflatInitPage(newbuf, newpage);
+
+			/* Update insert page */
+			insertPage = BufferGetBlockNumber(newbuf);
+
+			/* Update previous buffer */
+			IvfflatPageGetOpaque(page)->nextblkno = insertPage;
+
+			/* Commit */
+			MarkBufferDirty(newbuf);
+			MarkBufferDirty(buf);
+			GenericXLogFinish(state);
+
+			/* Unlock extend relation lock as early as possible */
+			UnlockReleaseBuffer(metabuf);
+
+			/* Unlock rest */
+			UnlockReleaseBuffer(newbuf);
+			UnlockReleaseBuffer(buf);
 		}
 	}
 

src/ivfkmeans.c

@@ -2,20 +2,8 @@
 
 #include <float.h>
 
-#include "catalog/index.h"
 #include "ivfflat.h"
 #include "miscadmin.h"
-#include "storage/bufmgr.h"
-
-#if PG_VERSION_NUM >= 120000
-#include "access/tableam.h"
-#endif
-
-#if PG_VERSION_NUM >= 130000
-#define CALLBACK_ITEM_POINTER ItemPointer tid
-#else
-#define CALLBACK_ITEM_POINTER HeapTuple hup
-#endif
 
 /*
  * Initialize with kmeans++
@@ -23,12 +11,12 @@
  * https://theory.stanford.edu/~sergei/papers/kMeansPP-soda.pdf
  */
 static void
-InitCenters(Relation index, VectorArray samples, VectorArray centers)
+InitCenters(Relation index, VectorArray samples, VectorArray centers, float *lowerBound)
 {
 	FmgrInfo   *procinfo;
 	Oid			collation;
 	int			i;
-	int			j;
+	int64		j;
 	double		distance;
 	double		sum;
 	double		choice;
@@ -41,13 +29,13 @@ InitCenters(Relation index, VectorArray samples, VectorArray centers)
 	collation = index->rd_indcollation[0];
 
 	/* Choose an initial center uniformly at random */
-	VectorArraySet(centers, 0, VectorArrayGet(samples, random() % samples->length));
+	VectorArraySet(centers, 0, VectorArrayGet(samples, RandomInt() % samples->length));
 	centers->length++;
 
 	for (j = 0; j < numSamples; j++)
 		weight[j] = DBL_MAX;
 
-	for (i = 0; i < numCenters - 1; i++)
+	for (i = 0; i < numCenters; i++)
 	{
 		CHECK_FOR_INTERRUPTS();
 
@@ -61,6 +49,9 @@ InitCenters(Relation index, VectorArray samples, VectorArray centers)
 			/* TODO Use triangle inequality to reduce distance calculations */
 			distance = DatumGetFloat8(FunctionCall2Coll(procinfo, collation, PointerGetDatum(vec), PointerGetDatum(VectorArrayGet(centers, i))));
 
+			/* Set lower bound */
+			lowerBound[j * numCenters + i] = distance;
+
 			/* Use distance squared for weighted probability distribution */
 			distance *= distance;
 
@@ -70,8 +61,12 @@ InitCenters(Relation index, VectorArray samples, VectorArray centers)
 			sum += weight[j];
 		}
 
+		/* Only compute lower bound on last iteration */
+		if (i + 1 == numCenters)
+			break;
+
 		/* Choose new center using weighted probability distribution. */
-		choice = sum * (((double) random()) / MAX_RANDOM_VALUE);
+		choice = sum * RandomDouble();
 		for (j = 0; j < numSamples - 1; j++)
 		{
 			choice -= weight[j];
@@ -150,7 +145,7 @@ QuickCenters(Relation index, VectorArray samples, VectorArray centers)
 		vec->dim = dimensions;
 
 		for (j = 0; j < dimensions; j++)
-			vec->x[j] = ((double) random()) / MAX_RANDOM_VALUE;
+			vec->x[j] = RandomDouble();
 
 		/* Normalize if needed (only needed for random centers) */
 		if (normprocinfo != NULL)
@@ -161,147 +156,108 @@ QuickCenters(Relation index, VectorArray samples, VectorArray centers)
 }
 
 /*
- * Callback for sampling
+ * Use Elkan for performance. This requires distance function to satisfy triangle inequality.
- */
-static void
-SampleCallback(Relation index, CALLBACK_ITEM_POINTER, Datum *values,
-			   bool *isnull, bool tupleIsAlive, void *state)
-{
-	IvfflatBuildState *buildstate = (IvfflatBuildState *) state;
-	VectorArray samples = buildstate->samples;
-	int			targsamples = samples->maxlen;
-	Datum		value = values[0];
-
-	/* Skip nulls */
-	if (isnull[0])
-		return;
-
-	/*
-	 * Normalize with KMEANS_NORM_PROC since spherical distance function
-	 * expects unit vectors
-	 */
-	if (buildstate->kmeansnormprocinfo != NULL)
-	{
-		if (!IvfflatNormValue(buildstate->kmeansnormprocinfo, buildstate->collation, &value, buildstate->normvec))
-			return;
-	}
-
-	if (samples->length < targsamples)
-	{
-		VectorArraySet(samples, samples->length, DatumGetVector(value));
-		samples->length++;
-	}
-	else
-	{
-		if (buildstate->rowstoskip < 0)
-			buildstate->rowstoskip = reservoir_get_next_S(&buildstate->rstate, samples->length, targsamples);
-
-		if (buildstate->rowstoskip <= 0)
-		{
-			int			k = (int) (targsamples * sampler_random_fract(buildstate->rstate.randstate));
-
-			Assert(k >= 0 && k < targsamples);
-			VectorArraySet(samples, k, DatumGetVector(value));
-		}
-
-		buildstate->rowstoskip -= 1;
-	}
-}
-
-/*
- * Sample rows with same logic as ANALYZE
- */
-static void
-SampleRows(IvfflatBuildState * buildstate)
-{
-	int			targsamples = buildstate->samples->maxlen;
-	BlockNumber totalblocks = RelationGetNumberOfBlocks(buildstate->heap);
-
-	buildstate->rowstoskip = -1;
-	buildstate->samples->length = 0;
-
-	BlockSampler_Init(&buildstate->bs, totalblocks, targsamples, random());
-
-	reservoir_init_selection_state(&buildstate->rstate, targsamples);
-	while (BlockSampler_HasMore(&buildstate->bs))
-	{
-		BlockNumber targblock = BlockSampler_Next(&buildstate->bs);
-
-#if PG_VERSION_NUM >= 120000
-		table_index_build_range_scan(buildstate->heap, buildstate->index, buildstate->indexInfo,
-									 false, true, false, targblock, 1, SampleCallback, (void *) buildstate, NULL);
-#elif PG_VERSION_NUM >= 110000
-		IndexBuildHeapRangeScan(buildstate->heap, buildstate->index, buildstate->indexInfo,
-								false, true, targblock, 1, SampleCallback, (void *) buildstate, NULL);
-#else
-		IndexBuildHeapRangeScan(buildstate->heap, buildstate->index, buildstate->indexInfo,
-								false, true, targblock, 1, SampleCallback, (void *) buildstate);
-#endif
-	}
-}
-
-/*
- * Use mini-batch k-means
  *
  * We use L2 distance for L2 (not L2 squared like index scan)
  * and angular distance for inner product and cosine distance
  *
- * https://www.eecs.tufts.edu/~dsculley/papers/fastkmeans.pdf
+ * https://www.aaai.org/Papers/ICML/2003/ICML03-022.pdf
  */
 static void
-MiniBatchKmeans(IvfflatBuildState * buildstate)
+ElkanKmeans(Relation index, VectorArray samples, VectorArray centers)
 {
-	VectorArray centers = buildstate->centers;
+	FmgrInfo   *procinfo;
-	VectorArray m = buildstate->samples;
+	FmgrInfo   *normprocinfo;
-	int			b = m->maxlen;
+	Oid			collation;
-	int			t = 20;
+	Vector	   *vec;
-	double		distance;
+	Vector	   *newCenter;
+	int			iteration;
+	int64		j;
+	int64		k;
+	int			dimensions = centers->dim;
+	int			numCenters = centers->maxlen;
+	int			numSamples = samples->length;
+	VectorArray newCenters;
+	int		   *centerCounts;
+	int		   *closestCenters;
+	float	   *lowerBound;
+	float	   *upperBound;
+	float	   *s;
+	float	   *halfcdist;
+	float	   *newcdist;
+	int			changes;
 	double		minDistance;
 	int			closestCenter;
-	int			i;
+	double		distance;
-	int			j;
+	bool		rj;
-	int			k;
+	bool		rjreset;
-	Vector	   *c;
+	double		dxcx;
-	Vector	   *x;
+	double		dxc;
-	int		   *v;
+
-	int		   *d;
+	/* Calculate allocation sizes */
-	double		eta;
+	Size		samplesSize = VECTOR_ARRAY_SIZE(samples->maxlen, samples->dim);
+	Size		centersSize = VECTOR_ARRAY_SIZE(centers->maxlen, centers->dim);
+	Size		newCentersSize = VECTOR_ARRAY_SIZE(numCenters, dimensions);
+	Size		centerCountsSize = sizeof(int) * numCenters;
+	Size		closestCentersSize = sizeof(int) * numSamples;
+	Size		lowerBoundSize = sizeof(float) * numSamples * numCenters;
+	Size		upperBoundSize = sizeof(float) * numSamples;
+	Size		sSize = sizeof(float) * numCenters;
+	Size		halfcdistSize = sizeof(float) * numCenters * numCenters;
+	Size		newcdistSize = sizeof(float) * numCenters;
+
+	/* Calculate total size */
+	Size		totalSize = samplesSize + centersSize + newCentersSize + centerCountsSize + closestCentersSize + lowerBoundSize + upperBoundSize + sSize + halfcdistSize + newcdistSize;
+
+	/* Check memory requirements */
+	/* Add one to error message to ceil */
+	if (totalSize / 1024 > maintenance_work_mem)
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("memory required is %zu MB, maintenance_work_mem is %d MB",
+						totalSize / (1024 * 1024) + 1, maintenance_work_mem / 1024)));
+
+	/* Ensure indexing does not overflow */
+	if (numCenters * numCenters > INT_MAX)
+		elog(ERROR, "Indexing overflow detected. Please report a bug.");
 
 	/* Set support functions */
-	FmgrInfo   *procinfo = index_getprocinfo(buildstate->index, 1, IVFFLAT_KMEANS_DISTANCE_PROC);
+	procinfo = index_getprocinfo(index, 1, IVFFLAT_KMEANS_DISTANCE_PROC);
-	FmgrInfo   *normprocinfo = buildstate->kmeansnormprocinfo;
+	normprocinfo = IvfflatOptionalProcInfo(index, IVFFLAT_KMEANS_NORM_PROC);
-	Oid			collation = buildstate->index->rd_indcollation[0];
+	collation = index->rd_indcollation[0];
+
+	/* Allocate space */
+	/* Use float instead of double to save memory */
+	centerCounts = palloc(centerCountsSize);
+	closestCenters = palloc(closestCentersSize);
+	lowerBound = palloc_extended(lowerBoundSize, MCXT_ALLOC_HUGE);
+	upperBound = palloc(upperBoundSize);
+	s = palloc(sSize);
+	halfcdist = palloc_extended(halfcdistSize, MCXT_ALLOC_HUGE);
+	newcdist = palloc(newcdistSize);
+
+	newCenters = VectorArrayInit(numCenters, dimensions);
+	for (j = 0; j < numCenters; j++)
+	{
+		vec = VectorArrayGet(newCenters, j);
+		SET_VARSIZE(vec, VECTOR_SIZE(dimensions));
+		vec->dim = dimensions;
+	}
 
 	/* Pick initial centers */
-	InitCenters(buildstate->index, buildstate->samples, buildstate->centers);
+	InitCenters(index, samples, centers, lowerBound);
 
-	v = palloc(sizeof(int) * centers->maxlen);
+	/* Assign each x to its closest initial center c(x) = argmin d(x,c) */
-	d = palloc(sizeof(int) * b);
+	for (j = 0; j < numSamples; j++)
-
-	for (int i = 0; i < centers->length; i++)
-		v[i] = 0;
-
-	for (i = 0; i < t; i++)
 	{
-		/* Can take a while, so ensure we can interrupt */
-		CHECK_FOR_INTERRUPTS();
-
-		/* Get b examples picked randomly from X */
-		SampleRows(buildstate);
-
-		/* Cache nearest center to x */
-		for (j = 0; j < m->length; j++)
-		{
-			/* compute closest */
 		minDistance = DBL_MAX;
 		closestCenter = -1;
 
-			x = VectorArrayGet(m, j);
-
 		/* Find closest center */
-			for (k = 0; k < centers->length; k++)
+		for (k = 0; k < numCenters; k++)
 		{
-				distance = DatumGetFloat8(FunctionCall2Coll(procinfo, collation, PointerGetDatum(x), PointerGetDatum(VectorArrayGet(centers, k))));
+			/* TODO Use Lemma 1 in k-means++ initialization */
+			distance = lowerBound[j * numCenters + k];
 
 			if (distance < minDistance)
 			{
@@ -310,53 +266,191 @@ MiniBatchKmeans(IvfflatBuildState * buildstate)
 			}
 		}
 
-			d[j] = closestCenter;
+		upperBound[j] = minDistance;
+		closestCenters[j] = closestCenter;
 	}
 
-		for (j = 0; j < m->length; j++)
+	/* Give 500 iterations to converge */
+	for (iteration = 0; iteration < 500; iteration++)
 	{
-			x = VectorArrayGet(m, j);
+		/* Can take a while, so ensure we can interrupt */
+		CHECK_FOR_INTERRUPTS();
 
-			/* Get cached center for this x */
+		changes = 0;
-			c = VectorArrayGet(centers, d[j]);
 
-			/* Update per-center counts */
+		/* Step 1: For all centers, compute distance */
-			v[d[j]]++;
+		for (j = 0; j < numCenters; j++)
+		{
+			vec = VectorArrayGet(centers, j);
 
-			/* Get per-center learning rate */
+			for (k = j + 1; k < numCenters; k++)
-			eta = 1.0 / v[d[j]];
+			{
-
+				distance = 0.5 * DatumGetFloat8(FunctionCall2Coll(procinfo, collation, PointerGetDatum(vec), PointerGetDatum(VectorArrayGet(centers, k))));
-			/* Take gradient step */
+				halfcdist[j * numCenters + k] = distance;
-			for (k = 0; k < c->dim; k++)
+				halfcdist[k * numCenters + j] = distance;
-				c->x[k] = (1 - eta) * c->x[k] + eta * x->x[k];
+			}
 		}
 
-		/* Check for empty centers (likely duplicates) */
+		/* For all centers c, compute s(c) */
-		if (i == 0)
+		for (j = 0; j < numCenters; j++)
 		{
-			for (j = 0; j < centers->length; j++)
+			minDistance = DBL_MAX;
-			{
-				if (v[j] == 0)
-				{
-					c = VectorArrayGet(centers, j);
 
+			for (k = 0; k < numCenters; k++)
+			{
+				if (j == k)
+					continue;
+
+				distance = halfcdist[j * numCenters + k];
+				if (distance < minDistance)
+					minDistance = distance;
+			}
+
+			s[j] = minDistance;
+		}
+
+		rjreset = iteration != 0;
+
+		for (j = 0; j < numSamples; j++)
+		{
+			/* Step 2: Identify all points x such that u(x) <= s(c(x)) */
+			if (upperBound[j] <= s[closestCenters[j]])
+				continue;
+
+			rj = rjreset;
+
+			for (k = 0; k < numCenters; k++)
+			{
+				/* Step 3: For all remaining points x and centers c */
+				if (k == closestCenters[j])
+					continue;
+
+				if (upperBound[j] <= lowerBound[j * numCenters + k])
+					continue;
+
+				if (upperBound[j] <= halfcdist[closestCenters[j] * numCenters + k])
+					continue;
+
+				vec = VectorArrayGet(samples, j);
+
+				/* Step 3a */
+				if (rj)
+				{
+					dxcx = DatumGetFloat8(FunctionCall2Coll(procinfo, collation, PointerGetDatum(vec), PointerGetDatum(VectorArrayGet(centers, closestCenters[j]))));
+
+					/* d(x,c(x)) computed, which is a form of d(x,c) */
+					lowerBound[j * numCenters + closestCenters[j]] = dxcx;
+					upperBound[j] = dxcx;
+
+					rj = false;
+				}
+				else
+					dxcx = upperBound[j];
+
+				/* Step 3b */
+				if (dxcx > lowerBound[j * numCenters + k] || dxcx > halfcdist[closestCenters[j] * numCenters + k])
+				{
+					dxc = DatumGetFloat8(FunctionCall2Coll(procinfo, collation, PointerGetDatum(vec), PointerGetDatum(VectorArrayGet(centers, k))));
+
+					/* d(x,c) calculated */
+					lowerBound[j * numCenters + k] = dxc;
+
+					if (dxc < dxcx)
+					{
+						closestCenters[j] = k;
+
+						/* c(x) changed */
+						upperBound[j] = dxc;
+
+						changes++;
+					}
+
+				}
+			}
+		}
+
+		/* Step 4: For each center c, let m(c) be mean of all points assigned */
+		for (j = 0; j < numCenters; j++)
+		{
+			vec = VectorArrayGet(newCenters, j);
+			for (k = 0; k < dimensions; k++)
+				vec->x[k] = 0.0;
+
+			centerCounts[j] = 0;
+		}
+
+		for (j = 0; j < numSamples; j++)
+		{
+			vec = VectorArrayGet(samples, j);
+			closestCenter = closestCenters[j];
+
+			/* Increment sum and count of closest center */
+			newCenter = VectorArrayGet(newCenters, closestCenter);
+			for (k = 0; k < dimensions; k++)
+				newCenter->x[k] += vec->x[k];
+
+			centerCounts[closestCenter] += 1;
+		}
+
+		for (j = 0; j < numCenters; j++)
+		{
+			vec = VectorArrayGet(newCenters, j);
+
+			if (centerCounts[j] > 0)
+			{
+				for (k = 0; k < dimensions; k++)
+					vec->x[k] /= centerCounts[j];
+			}
+			else
+			{
 				/* TODO Handle empty centers properly */
-					for (k = 0; k < c->dim; k++)
+				for (k = 0; k < dimensions; k++)
-						c->x[k] = ((double) random()) / MAX_RANDOM_VALUE;
+					vec->x[k] = RandomDouble();
-				}
-			}
 			}
 
 			/* Normalize if needed */
 			if (normprocinfo != NULL)
+				ApplyNorm(normprocinfo, collation, vec);
+		}
+
+		/* Step 5 */
+		for (j = 0; j < numCenters; j++)
+			newcdist[j] = DatumGetFloat8(FunctionCall2Coll(procinfo, collation, PointerGetDatum(VectorArrayGet(centers, j)), PointerGetDatum(VectorArrayGet(newCenters, j))));
+
+		for (j = 0; j < numSamples; j++)
 		{
-			for (j = 0; j < centers->length; j++)
+			for (k = 0; k < numCenters; k++)
-				ApplyNorm(normprocinfo, collation, VectorArrayGet(centers, j));
+			{
+				distance = lowerBound[j * numCenters + k] - newcdist[k];
+
+				if (distance < 0)
+					distance = 0;
+
+				lowerBound[j * numCenters + k] = distance;
 			}
 		}
 
-	pfree(v);
+		/* Step 6 */
-	pfree(d);
+		/* We reset r(x) before Step 3 in the next iteration */
+		for (j = 0; j < numSamples; j++)
+			upperBound[j] += newcdist[closestCenters[j]];
+
+		/* Step 7 */
+		for (j = 0; j < numCenters; j++)
+			memcpy(VectorArrayGet(centers, j), VectorArrayGet(newCenters, j), VECTOR_SIZE(dimensions));
+
+		if (changes == 0 && iteration != 0)
+			break;
+	}
+
+	VectorArrayFree(newCenters);
+	pfree(centerCounts);
+	pfree(closestCenters);
+	pfree(lowerBound);
+	pfree(upperBound);
+	pfree(s);
+	pfree(halfcdist);
+	pfree(newcdist);
 }
 
 /*
@@ -399,48 +493,16 @@ CheckCenters(Relation index, VectorArray centers)
 }
 
 /*
- * Perform k-means clustering
+ * Perform naive k-means centering
  * We use spherical k-means for inner product and cosine
  */
 void
-IvfflatKmeans(IvfflatBuildState * buildstate)
+IvfflatKmeans(Relation index, VectorArray samples, VectorArray centers)
 {
-	int			numSamples;
+	if (samples->length <= centers->maxlen)
-	Size		totalSize;
+		QuickCenters(index, samples, centers);
-
-	/* Target 10 samples per list, with at least 10000 samples */
-	/* The number of samples has a large effect on index build time */
-	numSamples = buildstate->lists * 10;
-	if (numSamples < 10000)
-		numSamples = 10000;
-
-	/* Skip samples for unlogged table */
-	if (buildstate->heap == NULL)
-		numSamples = 1;
-
-	/* Calculate total size */
-	totalSize = VECTOR_ARRAY_SIZE(numSamples, buildstate->dimensions);
-
-	/* Check memory requirements */
-	/* Add one to error message to ceil */
-	if (totalSize / 1024 > maintenance_work_mem)
-		ereport(ERROR,
-				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
-				 errmsg("memory required is %zu MB, maintenance_work_mem is %d MB",
-						totalSize / (1024 * 1024) + 1, maintenance_work_mem / 1024)));
-
-	/* Sample rows */
-	buildstate->samples = VectorArrayInit(numSamples, buildstate->dimensions);
-	if (buildstate->heap != NULL)
-		SampleRows(buildstate);
-
-	if (buildstate->samples->length <= buildstate->centers->maxlen)
-		QuickCenters(buildstate->index, buildstate->samples, buildstate->centers);
 	else
-		MiniBatchKmeans(buildstate);
+		ElkanKmeans(index, samples, centers);
 
-	CheckCenters(buildstate->index, buildstate->centers);
+	CheckCenters(index, centers);
-
-	/* Free samples before we allocate more memory */
-	pfree(buildstate->samples);
 }

src/ivfutils.c

@@ -10,14 +10,25 @@
 VectorArray
 VectorArrayInit(int maxlen, int dimensions)
 {
-	VectorArray res = palloc0(VECTOR_ARRAY_SIZE(maxlen, dimensions));
+	VectorArray res = palloc(sizeof(VectorArrayData));
 
 	res->length = 0;
 	res->maxlen = maxlen;
 	res->dim = dimensions;
+	res->items = palloc_extended(maxlen * VECTOR_SIZE(dimensions), MCXT_ALLOC_ZERO | MCXT_ALLOC_HUGE);
 	return res;
 }
 
+/*
+ * Free a vector array
+ */
+void
+VectorArrayFree(VectorArray arr)
+{
+	pfree(arr->items);
+	pfree(arr);
+}
+
 /*
  * Print vector array - useful for debugging
  */
@@ -107,13 +118,22 @@ IvfflatNewBuffer(Relation index, ForkNumber forkNum)
  * Init page
  */
 void
-IvfflatInitPage(Relation index, Buffer *buf, Page *page, GenericXLogState **state)
+IvfflatInitPage(Buffer buf, Page page)
+{
+	PageInit(page, BufferGetPageSize(buf), sizeof(IvfflatPageOpaqueData));
+	IvfflatPageGetOpaque(page)->nextblkno = InvalidBlockNumber;
+	IvfflatPageGetOpaque(page)->page_id = IVFFLAT_PAGE_ID;
+}
+
+/*
+ * Init and register page
+ */
+void
+IvfflatInitRegisterPage(Relation index, Buffer *buf, Page *page, GenericXLogState **state)
 {
 	*state = GenericXLogStart(index);
 	*page = GenericXLogRegisterBuffer(*state, *buf, GENERIC_XLOG_FULL_IMAGE);
-	PageInit(*page, BufferGetPageSize(*buf), sizeof(IvfflatPageOpaqueData));
+	IvfflatInitPage(*buf, *page);
-	IvfflatPageGetOpaque(*page)->nextblkno = InvalidBlockNumber;
-	IvfflatPageGetOpaque(*page)->page_id = IVFFLAT_PAGE_ID;
 }
 
 /*
@@ -135,17 +155,27 @@ IvfflatCommitBuffer(Buffer buf, GenericXLogState *state)
 void
 IvfflatAppendPage(Relation index, Buffer *buf, Page *page, GenericXLogState **state, ForkNumber forkNum)
 {
-	Buffer		prevbuf = *buf;
-
 	/* Get new buffer */
-	*buf = IvfflatNewBuffer(index, forkNum);
+	Buffer		newbuf = IvfflatNewBuffer(index, forkNum);
+	Page		newpage = GenericXLogRegisterBuffer(*state, newbuf, GENERIC_XLOG_FULL_IMAGE);
 
-	/* Update and commit previous buffer */
+	/* Update the previous buffer */
-	IvfflatPageGetOpaque(*page)->nextblkno = BufferGetBlockNumber(*buf);
+	IvfflatPageGetOpaque(*page)->nextblkno = BufferGetBlockNumber(newbuf);
-	IvfflatCommitBuffer(prevbuf, *state);
 
 	/* Init new page */
-	IvfflatInitPage(index, buf, page, state);
+	IvfflatInitPage(newbuf, newpage);
+
+	/* Commit */
+	MarkBufferDirty(*buf);
+	MarkBufferDirty(newbuf);
+	GenericXLogFinish(*state);
+
+	/* Unlock */
+	UnlockReleaseBuffer(*buf);
+
+	*state = GenericXLogStart(index);
+	*page = GenericXLogRegisterBuffer(*state, newbuf, GENERIC_XLOG_FULL_IMAGE);
+	*buf = newbuf;
 }
 
 /*

src/vector.c

@@ -13,7 +13,10 @@
 #include "utils/numeric.h"
 
 #if PG_VERSION_NUM >= 120000
+#include "common/shortest_dec.h"
 #include "utils/float.h"
+#else
+#include <float.h>
 #endif
 
 #if PG_VERSION_NUM < 130000
@@ -106,14 +109,14 @@ PrintVector(char *msg, Vector * vector)
 /*
  * Convert textual representation to internal representation
  */
-PG_FUNCTION_INFO_V1(vector_in);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_in);
 Datum
 vector_in(PG_FUNCTION_ARGS)
 {
 	char	   *str = PG_GETARG_CSTRING(0);
 	int32		typmod = PG_GETARG_INT32(2);
 	int			i;
-	double		x[VECTOR_MAX_DIM];
+	float		x[VECTOR_MAX_DIM];
 	int			dim = 0;
 	char	   *pt;
 	char	   *stringEnd;
@@ -136,7 +139,8 @@ vector_in(PG_FUNCTION_ARGS)
 					(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
 					 errmsg("vector cannot have more than %d dimensions", VECTOR_MAX_DIM)));
 
-		x[dim] = strtod(pt, &stringEnd);
+		/* Use strtof like float4in to avoid a double-rounding problem */
+		x[dim] = strtof(pt, &stringEnd);
 		CheckElement(x[dim]);
 		dim++;
 
@@ -182,35 +186,68 @@ vector_in(PG_FUNCTION_ARGS)
 /*
  * Convert internal representation to textual representation
  */
-PG_FUNCTION_INFO_V1(vector_out);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_out);
 Datum
 vector_out(PG_FUNCTION_ARGS)
 {
 	Vector	   *vector = PG_GETARG_VECTOR_P(0);
-	StringInfoData buf;
 	int			dim = vector->dim;
+	char	   *buf;
+	char	   *ptr;
 	int			i;
+	int			n;
 
-	initStringInfo(&buf);
+#if PG_VERSION_NUM < 120000
+	int			ndig = FLT_DIG + extra_float_digits;
 
-	appendStringInfoChar(&buf, '[');
+	if (ndig < 1)
+		ndig = 1;
+
+#define FLOAT_SHORTEST_DECIMAL_LEN (ndig + 10)
+#endif
+
+	/*
+	 * Need:
+	 *
+	 * dim * (FLOAT_SHORTEST_DECIMAL_LEN - 1) bytes for
+	 * float_to_shortest_decimal_bufn
+	 *
+	 * dim - 1 bytes for separator
+	 *
+	 * 3 bytes for [, ], and \0
+	 */
+	buf = (char *) palloc(FLOAT_SHORTEST_DECIMAL_LEN * dim + 2);
+	ptr = buf;
+
+	*ptr = '[';
+	ptr++;
 	for (i = 0; i < dim; i++)
 	{
 		if (i > 0)
-			appendStringInfoString(&buf, ",");
+		{
-
+			*ptr = ',';
-		appendStringInfoString(&buf, float8out_internal(vector->x[i]));
+			ptr++;
 		}
-	appendStringInfoChar(&buf, ']');
+
+#if PG_VERSION_NUM >= 120000
+		n = float_to_shortest_decimal_bufn(vector->x[i], ptr);
+#else
+		n = sprintf(ptr, "%.*g", ndig, vector->x[i]);
+#endif
+		ptr += n;
+	}
+	*ptr = ']';
+	ptr++;
+	*ptr = '\0';
 
 	PG_FREE_IF_COPY(vector, 0);
-	PG_RETURN_CSTRING(buf.data);
+	PG_RETURN_CSTRING(buf);
 }
 
 /*
  * Convert type modifier
  */
-PG_FUNCTION_INFO_V1(vector_typmod_in);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_typmod_in);
 Datum
 vector_typmod_in(PG_FUNCTION_ARGS)
 {
@@ -241,7 +278,7 @@ vector_typmod_in(PG_FUNCTION_ARGS)
 /*
  * Convert external binary representation to internal representation
  */
-PG_FUNCTION_INFO_V1(vector_recv);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_recv);
 Datum
 vector_recv(PG_FUNCTION_ARGS)
 {
@@ -273,7 +310,7 @@ vector_recv(PG_FUNCTION_ARGS)
 /*
  * Convert internal representation to the external binary representation
  */
-PG_FUNCTION_INFO_V1(vector_send);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_send);
 Datum
 vector_send(PG_FUNCTION_ARGS)
 {
@@ -293,7 +330,7 @@ vector_send(PG_FUNCTION_ARGS)
 /*
  * Convert vector to vector
  */
-PG_FUNCTION_INFO_V1(vector);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector);
 Datum
 vector(PG_FUNCTION_ARGS)
 {
@@ -308,7 +345,7 @@ vector(PG_FUNCTION_ARGS)
 /*
  * Convert array to vector
  */
-PG_FUNCTION_INFO_V1(array_to_vector);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(array_to_vector);
 Datum
 array_to_vector(PG_FUNCTION_ARGS)
 {
@@ -366,7 +403,7 @@ array_to_vector(PG_FUNCTION_ARGS)
 /*
  * Convert vector to float4[]
  */
-PG_FUNCTION_INFO_V1(vector_to_float4);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_to_float4);
 Datum
 vector_to_float4(PG_FUNCTION_ARGS)
 {
@@ -389,12 +426,14 @@ vector_to_float4(PG_FUNCTION_ARGS)
 /*
  * Get the L2 distance between vectors
  */
-PG_FUNCTION_INFO_V1(l2_distance);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(l2_distance);
 Datum
 l2_distance(PG_FUNCTION_ARGS)
 {
 	Vector	   *a = PG_GETARG_VECTOR_P(0);
 	Vector	   *b = PG_GETARG_VECTOR_P(1);
+	float	   *ax = a->x;
+	float	   *bx = b->x;
 	double		distance = 0.0;
 	double		diff;
 
@@ -402,7 +441,7 @@ l2_distance(PG_FUNCTION_ARGS)
 
 	for (int i = 0; i < a->dim; i++)
 	{
-		diff = a->x[i] - b->x[i];
+		diff = ax[i] - bx[i];
 		distance += diff * diff;
 	}
 
@@ -413,12 +452,14 @@ l2_distance(PG_FUNCTION_ARGS)
  * Get the L2 squared distance between vectors
  * This saves a sqrt calculation
  */
-PG_FUNCTION_INFO_V1(vector_l2_squared_distance);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_l2_squared_distance);
 Datum
 vector_l2_squared_distance(PG_FUNCTION_ARGS)
 {
 	Vector	   *a = PG_GETARG_VECTOR_P(0);
 	Vector	   *b = PG_GETARG_VECTOR_P(1);
+	float	   *ax = a->x;
+	float	   *bx = b->x;
 	double		distance = 0.0;
 	double		diff;
 
@@ -426,7 +467,7 @@ vector_l2_squared_distance(PG_FUNCTION_ARGS)
 
 	for (int i = 0; i < a->dim; i++)
 	{
-		diff = a->x[i] - b->x[i];
+		diff = ax[i] - bx[i];
 		distance += diff * diff;
 	}
 
@@ -436,18 +477,20 @@ vector_l2_squared_distance(PG_FUNCTION_ARGS)
 /*
  * Get the inner product of two vectors
  */
-PG_FUNCTION_INFO_V1(inner_product);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(inner_product);
 Datum
 inner_product(PG_FUNCTION_ARGS)
 {
 	Vector	   *a = PG_GETARG_VECTOR_P(0);
 	Vector	   *b = PG_GETARG_VECTOR_P(1);
+	float	   *ax = a->x;
+	float	   *bx = b->x;
 	double		distance = 0.0;
 
 	CheckDims(a, b);
 
 	for (int i = 0; i < a->dim; i++)
-		distance += a->x[i] * b->x[i];
+		distance += ax[i] * bx[i];
 
 	PG_RETURN_FLOAT8(distance);
 }
@@ -455,18 +498,20 @@ inner_product(PG_FUNCTION_ARGS)
 /*
  * Get the negative inner product of two vectors
  */
-PG_FUNCTION_INFO_V1(vector_negative_inner_product);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_negative_inner_product);
 Datum
 vector_negative_inner_product(PG_FUNCTION_ARGS)
 {
 	Vector	   *a = PG_GETARG_VECTOR_P(0);
 	Vector	   *b = PG_GETARG_VECTOR_P(1);
+	float	   *ax = a->x;
+	float	   *bx = b->x;
 	double		distance = 0.0;
 
 	CheckDims(a, b);
 
 	for (int i = 0; i < a->dim; i++)
-		distance += a->x[i] * b->x[i];
+		distance += ax[i] * bx[i];
 
 	PG_RETURN_FLOAT8(distance * -1);
 }
@@ -474,12 +519,14 @@ vector_negative_inner_product(PG_FUNCTION_ARGS)
 /*
  * Get the cosine distance between two vectors
  */
-PG_FUNCTION_INFO_V1(cosine_distance);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(cosine_distance);
 Datum
 cosine_distance(PG_FUNCTION_ARGS)
 {
 	Vector	   *a = PG_GETARG_VECTOR_P(0);
 	Vector	   *b = PG_GETARG_VECTOR_P(1);
+	float	   *ax = a->x;
+	float	   *bx = b->x;
 	double		distance = 0.0;
 	double		norma = 0.0;
 	double		normb = 0.0;
@@ -488,9 +535,9 @@ cosine_distance(PG_FUNCTION_ARGS)
 
 	for (int i = 0; i < a->dim; i++)
 	{
-		distance += a->x[i] * b->x[i];
+		distance += ax[i] * bx[i];
-		norma += a->x[i] * a->x[i];
+		norma += ax[i] * ax[i];
-		normb += b->x[i] * b->x[i];
+		normb += bx[i] * bx[i];
 	}
 
 	PG_RETURN_FLOAT8(1 - (distance / (sqrt(norma) * sqrt(normb))));
@@ -501,7 +548,7 @@ cosine_distance(PG_FUNCTION_ARGS)
  * Currently uses angular distance since needs to satisfy triangle inequality
  * Assumes inputs are unit vectors (skips norm)
  */
-PG_FUNCTION_INFO_V1(vector_spherical_distance);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_spherical_distance);
 Datum
 vector_spherical_distance(PG_FUNCTION_ARGS)
 {
@@ -526,7 +573,7 @@ vector_spherical_distance(PG_FUNCTION_ARGS)
 /*
  * Get the dimensions of a vector
  */
-PG_FUNCTION_INFO_V1(vector_dims);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_dims);
 Datum
 vector_dims(PG_FUNCTION_ARGS)
 {
@@ -538,15 +585,16 @@ vector_dims(PG_FUNCTION_ARGS)
 /*
  * Get the L2 norm of a vector
  */
-PG_FUNCTION_INFO_V1(vector_norm);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_norm);
 Datum
 vector_norm(PG_FUNCTION_ARGS)
 {
 	Vector	   *a = PG_GETARG_VECTOR_P(0);
+	float	   *ax = a->x;
 	double		norm = 0.0;
 
 	for (int i = 0; i < a->dim; i++)
-		norm += a->x[i] * a->x[i];
+		norm += ax[i] * ax[i];
 
 	PG_RETURN_FLOAT8(sqrt(norm));
 }
@@ -554,20 +602,23 @@ vector_norm(PG_FUNCTION_ARGS)
 /*
  * Add vectors
  */
-PG_FUNCTION_INFO_V1(vector_add);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_add);
 Datum
 vector_add(PG_FUNCTION_ARGS)
 {
 	Vector	   *a = PG_GETARG_VECTOR_P(0);
 	Vector	   *b = PG_GETARG_VECTOR_P(1);
+	float	   *ax = a->x;
+	float	   *bx = b->x;
 	Vector	   *result;
-	int			i;
+	float	   *rx;
 
 	CheckDims(a, b);
 
 	result = InitVector(a->dim);
-	for (i = 0; i < a->dim; i++)
+	rx = result->x;
-		result->x[i] = a->x[i] + b->x[i];
+	for (int i = 0, imax = a->dim; i < imax; i++)
+		rx[i] = ax[i] + bx[i];
 
 	PG_RETURN_POINTER(result);
 }
@@ -575,20 +626,23 @@ vector_add(PG_FUNCTION_ARGS)
 /*
  * Subtract vectors
  */
-PG_FUNCTION_INFO_V1(vector_sub);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_sub);
 Datum
 vector_sub(PG_FUNCTION_ARGS)
 {
 	Vector	   *a = PG_GETARG_VECTOR_P(0);
 	Vector	   *b = PG_GETARG_VECTOR_P(1);
+	float	   *ax = a->x;
+	float	   *bx = b->x;
 	Vector	   *result;
-	int			i;
+	float	   *rx;
 
 	CheckDims(a, b);
 
 	result = InitVector(a->dim);
-	for (i = 0; i < a->dim; i++)
+	rx = result->x;
-		result->x[i] = a->x[i] - b->x[i];
+	for (int i = 0, imax = a->dim; i < imax; i++)
+		rx[i] = ax[i] - bx[i];
 
 	PG_RETURN_POINTER(result);
 }
@@ -617,7 +671,7 @@ vector_cmp_internal(Vector * a, Vector * b)
 /*
  * Less than
  */
-PG_FUNCTION_INFO_V1(vector_lt);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_lt);
 Datum
 vector_lt(PG_FUNCTION_ARGS)
 {
@@ -630,7 +684,7 @@ vector_lt(PG_FUNCTION_ARGS)
 /*
  * Less than or equal
  */
-PG_FUNCTION_INFO_V1(vector_le);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_le);
 Datum
 vector_le(PG_FUNCTION_ARGS)
 {
@@ -643,7 +697,7 @@ vector_le(PG_FUNCTION_ARGS)
 /*
  * Equal
  */
-PG_FUNCTION_INFO_V1(vector_eq);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_eq);
 Datum
 vector_eq(PG_FUNCTION_ARGS)
 {
@@ -656,7 +710,7 @@ vector_eq(PG_FUNCTION_ARGS)
 /*
  * Not equal
  */
-PG_FUNCTION_INFO_V1(vector_ne);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_ne);
 Datum
 vector_ne(PG_FUNCTION_ARGS)
 {
@@ -669,7 +723,7 @@ vector_ne(PG_FUNCTION_ARGS)
 /*
  * Greater than or equal
  */
-PG_FUNCTION_INFO_V1(vector_ge);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_ge);
 Datum
 vector_ge(PG_FUNCTION_ARGS)
 {
@@ -682,7 +736,7 @@ vector_ge(PG_FUNCTION_ARGS)
 /*
  * Greater than
  */
-PG_FUNCTION_INFO_V1(vector_gt);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_gt);
 Datum
 vector_gt(PG_FUNCTION_ARGS)
 {
@@ -695,7 +749,7 @@ vector_gt(PG_FUNCTION_ARGS)
 /*
  * Compare vectors
  */
-PG_FUNCTION_INFO_V1(vector_cmp);
+PGDLLEXPORT PG_FUNCTION_INFO_V1(vector_cmp);
 Datum
 vector_cmp(PG_FUNCTION_ARGS)
 {

test/expected/btree.out

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 CREATE TABLE t (val vector(3));
 INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);

test/expected/cast.out

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SELECT ARRAY[1,2,3]::vector;
   array  
 ---------

test/expected/copy.out

@@ -1,10 +1,8 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 CREATE TABLE t (val vector(3));
 INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
 CREATE TABLE t2 (val vector(3));
-\copy t TO '/tmp/data.bin' WITH (FORMAT binary)
+\copy t TO 'results/data.bin' WITH (FORMAT binary)
-\copy t2 FROM '/tmp/data.bin' WITH (FORMAT binary)
+\copy t2 FROM 'results/data.bin' WITH (FORMAT binary)
 SELECT * FROM t2 ORDER BY val;
    val   
 ---------

test/expected/functions.out

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SELECT '[1,2,3]'::vector + '[4,5,6]';
  ?column? 
 ----------

test/expected/input.out

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SELECT '[1,2,3]'::vector;
  vector  
 ---------
@@ -12,6 +10,12 @@ SELECT '[-1,2,3]'::vector;
  [-1,2,3]
 (1 row)
 
+SELECT '[1.23456]'::vector;
+  vector   
+-----------
+ [1.23456]
+(1 row)
+
 SELECT '[hello,1]'::vector;
 ERROR:  invalid input syntax for type vector: "hello"
 LINE 1: SELECT '[hello,1]'::vector;

test/expected/ivfflat_cosine.out

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 CREATE TABLE t (val vector(3));
 INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);

test/expected/ivfflat_ip.out

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 CREATE TABLE t (val vector(3));
 INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);

test/expected/ivfflat_l2.out

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 CREATE TABLE t (val vector(3));
 INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);

test/expected/ivfflat_options.out

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 CREATE TABLE t (val vector(3));
 CREATE INDEX ON t USING ivfflat (val) WITH (lists = 0);

test/expected/ivfflat_unlogged.out

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 CREATE UNLOGGED TABLE t (val vector(3));
 INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);

test/perl/PostgresNode.pm

@@ -0,0 +1,8 @@
+use PostgreSQL::Test::Cluster;
+
+sub get_new_node
+{
+	return PostgreSQL::Test::Cluster->new(@_);
+}
+
+1;

test/perl/TestLib.pm

@@ -0,0 +1,3 @@
+use PostgreSQL::Test::Utils;
+
+1;

test/sql/btree.sql

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 
 CREATE TABLE t (val vector(3));

test/sql/cast.sql

@@ -1,6 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
-
 SELECT ARRAY[1,2,3]::vector;
 SELECT ARRAY[1.0,2.0,3.0]::vector;
 SELECT ARRAY[1,2,3]::float4[]::vector;

test/sql/copy.sql

@@ -1,13 +1,10 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
-
 CREATE TABLE t (val vector(3));
 INSERT INTO t (val) VALUES ('[0,0,0]'), ('[1,2,3]'), ('[1,1,1]'), (NULL);
 
 CREATE TABLE t2 (val vector(3));
 
-\copy t TO '/tmp/data.bin' WITH (FORMAT binary)
+\copy t TO 'results/data.bin' WITH (FORMAT binary)
-\copy t2 FROM '/tmp/data.bin' WITH (FORMAT binary)
+\copy t2 FROM 'results/data.bin' WITH (FORMAT binary)
 
 SELECT * FROM t2 ORDER BY val;
 

test/sql/functions.sql

@@ -1,6 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
-
 SELECT '[1,2,3]'::vector + '[4,5,6]';
 SELECT '[1,2,3]'::vector - '[4,5,6]';
 

test/sql/input.sql

@@ -1,8 +1,6 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
-
 SELECT '[1,2,3]'::vector;
 SELECT '[-1,2,3]'::vector;
+SELECT '[1.23456]'::vector;
 SELECT '[hello,1]'::vector;
 SELECT '[NaN,1]'::vector;
 SELECT '[Infinity,1]'::vector;

test/sql/ivfflat_cosine.sql

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 
 CREATE TABLE t (val vector(3));

test/sql/ivfflat_ip.sql

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 
 CREATE TABLE t (val vector(3));

test/sql/ivfflat_l2.sql

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 
 CREATE TABLE t (val vector(3));

test/sql/ivfflat_options.sql

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 
 CREATE TABLE t (val vector(3));

test/sql/ivfflat_unlogged.sql

@@ -1,5 +1,3 @@
-SET client_min_messages = warning;
-CREATE EXTENSION IF NOT EXISTS vector;
 SET enable_seqscan = off;
 
 CREATE UNLOGGED TABLE t (val vector(3));

test/t/001_wal.pl

@@ -7,6 +7,8 @@ use PostgresNode;
 use TestLib;
 use Test::More tests => 31;
 
+my $dim = 32;
+
 my $node_primary;
 my $node_replica;
 
@@ -30,13 +32,15 @@ sub test_index_replay
 	$node_primary->poll_query_until('postgres', $caughtup_query)
 	  or die "Timed out while waiting for replica 1 to catch up";
 
-	my $r1 = rand();
+	my @r = ();
-	my $r2 = rand();
+	for (1 .. $dim) {
-	my $r3 = rand();
+		push(@r, rand());
+	}
+	my $sql = join(",", @r);
 
 	my $queries = qq(
 		SET enable_seqscan = off;
-		SELECT * FROM tst ORDER BY v <-> '[$r1,$r2,$r3]' LIMIT 10;
+		SELECT * FROM tst ORDER BY v <-> '[$sql]' LIMIT 10;
 	);
 
 	# Run test queries and compare their result
@@ -47,9 +51,18 @@ sub test_index_replay
 	return;
 }
 
+# Use ARRAY[random(), random(), random(), ...] over
+# SELECT array_agg(random()) FROM generate_series(1, $dim)
+# to generate different values for each row
+my $array_sql = join(",", ('random()') x $dim);
+
 # Initialize primary node
 $node_primary = get_new_node('primary');
 $node_primary->init(allows_streaming => 1);
+if ($dim > 32) {
+	# TODO use wal_keep_segments for Postgres < 13
+	$node_primary->append_conf('postgresql.conf', qq(wal_keep_size = 1GB));
+}
 $node_primary->start;
 my $backup_name = 'my_backup';
 
@@ -64,9 +77,9 @@ $node_replica->start;
 
 # Create ivfflat index on primary
 $node_primary->safe_psql("postgres", "CREATE EXTENSION vector;");
-$node_primary->safe_psql("postgres", "CREATE TABLE tst (i int4, v vector(3));");
+$node_primary->safe_psql("postgres", "CREATE TABLE tst (i int4, v vector($dim));");
 $node_primary->safe_psql("postgres",
-	"INSERT INTO tst SELECT i % 10, ARRAY[random(), random(), random()] FROM generate_series(1, 100000) i;"
+	"INSERT INTO tst SELECT i % 10, ARRAY[$array_sql] FROM generate_series(1, 100000) i;"
 );
 $node_primary->safe_psql("postgres", "CREATE INDEX ON tst USING ivfflat (v);");
 
@@ -82,7 +95,7 @@ for my $i (1 .. 10)
 	test_index_replay("vacuum $i");
 	my ($start, $end) = (100001 + ($i - 1) * 10000, 100000 + $i * 10000);
 	$node_primary->safe_psql("postgres",
-		"INSERT INTO tst SELECT i % 10, ARRAY[random(), random(), random()] FROM generate_series($start, $end) i;"
+		"INSERT INTO tst SELECT i % 10, ARRAY[$array_sql] FROM generate_series($start, $end) i;"
 	);
 	test_index_replay("insert $i");
 }

test/t/007_inserts.pl

@@ -0,0 +1,45 @@
+use strict;
+use warnings;
+use PostgresNode;
+use TestLib;
+use Test::More tests => 5;
+
+my $dim = 768;
+
+my $array_sql = join(",", ('random()') x $dim);
+
+# Initialize node
+my $node = get_new_node('node');
+$node->init;
+$node->start;
+
+# Create table and index
+$node->safe_psql("postgres", "CREATE EXTENSION vector;");
+$node->safe_psql("postgres", "CREATE TABLE tst (v vector($dim));");
+$node->safe_psql("postgres",
+	"INSERT INTO tst SELECT ARRAY[$array_sql] FROM generate_series(1, 10000) i;"
+);
+$node->safe_psql("postgres", "CREATE INDEX ON tst USING ivfflat (v);");
+
+$node->pgbench(
+	"--no-vacuum --client=5 --transactions=100",
+	0,
+	[qr{actually processed}],
+	[qr{^$}],
+	"concurrent INSERTs",
+	{
+		"007_inserts" => "INSERT INTO tst SELECT ARRAY[$array_sql] FROM generate_series(1, 10) i;"
+	}
+);
+
+my $expected = 10000 + 5 * 100 * 10;
+
+my $count = $node->safe_psql("postgres", "SELECT COUNT(*) FROM tst;");
+is($count, $expected);
+
+$count = $node->safe_psql("postgres", qq(
+	SET enable_seqscan = off;
+	SET ivfflat.probes = 100;
+	SELECT COUNT(*) FROM (SELECT v FROM tst ORDER BY v <-> (SELECT v FROM tst LIMIT 1)) t;
+));
+is($count, $expected);

vector.control

@@ -1,4 +1,4 @@
 comment = 'vector data type and ivfflat access method'
-default_version = '0.2.5'
+default_version = '0.3.2'
 module_pathname = '$libdir/vector'
 relocatable = true