Pg textsearch0.3.0

use-timescale/extensions/pg-textsearch.md

@@ -8,14 +8,18 @@ products: [cloud, self_hosted]
 
 import EA1125 from "versionContent/_partials/_early_access_11_25.mdx";
 import SINCE010 from "versionContent/_partials/_since_0_1_0.mdx";
+import SINCE040 from "versionContent/_partials/_since_0_4_0.mdx";
 import IntegrationPrereqs from "versionContent/_partials/_integration-prereqs.mdx";
 
 # Optimize full text search with BM25 
 
-$PG full-text search at scale consistently hits a wall where performance degrades catastrophically. 
+$PG full-text search at scale consistently hits a wall where performance degrades catastrophically.
 $COMPANY's [pg_textsearch][pg_textsearch-github-repo] brings modern [BM25][bm25-wiki]-based full-text search directly into $PG,
-with a memtable architecture for efficient indexing and ranking. `pg_textsearch` integrates seamlessly with SQL and 
-provides better search quality and performance than the $PG built-in full-text search.
+with a memtable architecture for efficient indexing and ranking. `pg_textsearch` integrates seamlessly with SQL and
+provides better search quality and performance than the $PG built-in full-text search. With Block-Max WAND optimization,
+`pg_textsearch` delivers up to **4x faster top-k queries** compared to naive BM25 implementations. Advanced compression
+using delta encoding and bitpacking reduces index sizes by **41%** while improving query performance by 10-20% for
+shorter queries.
 
 BM25 scores in `pg_textsearch` are returned as negative values, where lower (more negative) numbers indicate better 
 matches. `pg_textsearch` implements the following:
@@ -117,7 +121,8 @@ You have created a BM25 index for full-text search.
 
 ## Optimize search queries for performance
 
-Use efficient query patterns to leverage BM25 ranking and optimize search performance.
+Use efficient query patterns to leverage BM25 ranking and optimize search performance. The `<@>` operator with `to_bm25query()`
+provides BM25-based ranking scores. The function takes two parameters: the search query text and the index name.
 
 <Procedure>
 
@@ -163,7 +168,7 @@ Use efficient query patterns to leverage BM25 ranking and optimize search perfor
    FROM products
    WHERE price < 500
      AND description <@> to_bm25query('ergonomic', 'products_search_idx') < -0.5
-   ORDER BY description <@> to_bm25query('ergonomic', 'products_search_idx')
+   ORDER BY score
    LIMIT 5;
    ```
 
@@ -350,9 +355,22 @@ Customize `pg_textsearch` behavior for your specific use case and data character
 
    -- Set default query limit when no LIMIT clause is present (default 1000)
    SET pg_textsearch.default_limit = 5000;
+
+   -- Enable Block-Max WAND optimization for faster top-k queries (enabled by default)
+   SET pg_textsearch.enable_bmw = true;
+
+   -- Log block skip statistics for debugging query performance (disabled by default)
+   SET pg_textsearch.log_bmw_stats = false;
    ```
    <SINCE010 />
 
+   ```sql
+   -- Enable segment compression using delta encoding and bitpacking (enabled by default)
+   -- Reduces index size by ~41% with 10-20% query performance improvement for shorter queries
+   SET pg_textsearch.compress_segments = on;
+   ```
+   <SINCE040 />
+
 1. **Configure language-specific text processing**
 
    You can create multiple BM25 indexes on the same column with different language configurations: