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Author SHA1 Message Date
Andrew Kane
bb72a6c063 Test BufferAccessStrategy [skip ci] 2023-04-10 22:07:58 -07:00
5 changed files with 10 additions and 18 deletions

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@@ -1,7 +1,6 @@
## 0.4.2 (unreleased)
- Added notice when index created with little data
- Fixed installation error with Postgres 12.0-12.2
## 0.4.1 (2023-03-21)

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@@ -2,11 +2,7 @@
Open-source vector similarity search for Postgres
Supports
- exact and approximate nearest neighbor search
- L2 distance, inner product, and cosine distance
- any [language](#languages) with a Postgres client
Supports exact and approximate nearest neighbor search for L2 distance, inner product, and cosine distance
[![Build Status](https://github.com/pgvector/pgvector/workflows/build/badge.svg?branch=master)](https://github.com/pgvector/pgvector/actions)
@@ -40,7 +36,7 @@ Create a vector column with 3 dimensions
CREATE TABLE items (id bigserial PRIMARY KEY, embedding vector(3));
```
Insert vectors
Insert values
```sql
INSERT INTO items (embedding) VALUES ('[1,2,3]'), ('[4,5,6]');
@@ -128,7 +124,7 @@ SELECT embedding <-> '[3,1,2]' AS distance FROM items;
For inner product, multiply by -1 (since `<#>` returns the negative inner product)
```sql
SELECT (embedding <#> '[3,1,2]') * -1 AS inner_product FROM items;
SELECT -1 * (embedding <#> '[3,1,2]') AS inner_product FROM items;
```
For cosine similarity, use 1 - cosine distance
@@ -137,7 +133,7 @@ For cosine similarity, use 1 - cosine distance
SELECT 1 - (embedding <=> '[3,1,2]') AS cosine_similarity FROM items;
```
#### Aggregates
#### Averaging
Average vectors
@@ -160,8 +156,8 @@ You can add an index to use approximate nearest neighbor search, which trades so
Three keys to achieving good recall are:
1. Create the index *after* the table has some data
2. Choose an appropriate number of lists - a good place to start is `rows / 1000` for up to 1M rows and `sqrt(rows)` for over 1M rows
3. When querying, specify an appropriate number of [probes](#query-options) (higher is better for recall, lower is better for speed) - a good place to start is `lists / 10` for up to 1M rows and `sqrt(lists)` for over 1M rows
2. Choose an appropriate number of lists (a good place to start is `rows / 1000` for up to 1M rows and `sqrt(rows)` for over 1M rows)
3. When querying, specify an appropriate number of [probes](#query-options) (higher is better for recall, lower is better for speed)
Add an index for each distance function you want to use.
@@ -279,10 +275,8 @@ Language | Libraries / Examples
--- | ---
C++ | [pgvector-cpp](https://github.com/pgvector/pgvector-cpp)
C# | [pgvector-dotnet](https://github.com/pgvector/pgvector-dotnet)
Crystal | [pgvector-crystal](https://github.com/pgvector/pgvector-crystal)
Elixir | [pgvector-elixir](https://github.com/pgvector/pgvector-elixir)
Go | [pgvector-go](https://github.com/pgvector/pgvector-go)
Haskell | [pgvector-haskell](https://github.com/pgvector/pgvector-haskell)
Java, Scala | [pgvector-java](https://github.com/pgvector/pgvector-java)
Julia | [pgvector-julia](https://github.com/pgvector/pgvector-julia)
Lua | [pgvector-lua](https://github.com/pgvector/pgvector-lua)
@@ -293,7 +287,6 @@ Python | [pgvector-python](https://github.com/pgvector/pgvector-python)
R | [pgvector-r](https://github.com/pgvector/pgvector-r)
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)
## Frequently Asked Questions
@@ -448,7 +441,7 @@ To request a new extension on other providers:
- Google Cloud SQL - vote or comment on [this page](https://issuetracker.google.com/issues/265172065)
- Azure Database - vote or comment on [this page](https://feedback.azure.com/d365community/idea/7b423322-6189-ed11-a81b-000d3ae49307)
- DigitalOcean Managed Databases - vote or comment on [this page](https://ideas.digitalocean.com/app-framework-services/p/pgvector-extension-for-postgresql)
- Heroku Postgres - vote or comment on [this page](https://github.com/heroku/roadmap/issues/156)
- Render - vote or comment on [this page](https://feedback.render.com/features/p/add-pgvector-extension-to-postgresql)
## Upgrading

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@@ -419,7 +419,7 @@ ComputeCenters(IvfflatBuildState * buildstate)
/* 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 * 200;
numSamples = buildstate->lists * 50;
if (numSamples < 10000)
numSamples = 10000;

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@@ -124,7 +124,7 @@ GetScanItems(IndexScanDesc scan, Datum value)
*
* See postgres/src/backend/storage/buffer/README for description
*/
BufferAccessStrategy bas = GetAccessStrategy(BAS_BULKREAD);
BufferAccessStrategy bas = GetAccessStrategy(BAS_NORMAL);
/* Search closest probes lists */
while (!pairingheap_is_empty(so->listQueue))

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@@ -100,7 +100,7 @@ CheckStateArray(ArrayType *statearray, const char *caller)
return (float8 *) ARR_DATA_PTR(statearray);
}
#if PG_VERSION_NUM < 120003
#if PG_VERSION_NUM < 120000
static pg_noinline void
float_overflow_error(void)
{