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Release History & API Evolution

Version changelog and SQL schema evolution of VectorChord-BM25 (vchord_bm25) from v0.1.0 to v0.3.0 and main.
Important

Current source targets 0.4.0 (unreleased), with native tsvector and a new index format. Examples labeled 0.3.x use the historical bm25vector API. In-place upgrades are blocked; read the 0.4.0 migration guide before changing binaries.

This page tracks the release history and SQL schema evolution of vchord_bm25 (pgsty/vchord_bm25 / supervc-stack/VectorChord-bm25).

Version Summary Matrix

Version Schema Indexed Type Tokenizer Key Additions
0.4.0 / main (unreleased) Extension schema tsvector Native to_tsvector (or custom) Complete storage & index engine rewrite on native tsvector; external sort parallel ambuild; index reloptions (options, limit, prefilter); bm25.* GUCs; PostgreSQL 18 support.
v0.3.0 bm25_catalog bm25vector pg_tokenizer Added bm25_page_inspect(regclass, int), to_bm25query(regclass, int[]) overload, and PostgreSQL 18 compatibility.
v0.2.2 bm25_catalog bm25vector pg_tokenizer Added bm25_catalog.enable_prefilter GUC for accurate filtered Top-K BM25 search with WHERE clauses.
v0.2.1 bm25_catalog bm25vector pg_tokenizer Bug fixes for growing/sealed segment transitions and vacuum cleanup.
v0.2.0 bm25_catalog bm25vector pg_tokenizer Added = and <> equality operators on bm25vector and implicit cast CREATE CAST (int[] AS bm25vector) AS IMPLICIT.
v0.1.1 bm25_catalog bm25vector pg_tokenizer Decoupled tokenization into standalone pg_tokenizer extension; changed to_bm25query(regclass, bm25vector) signature.
v0.1.0 bm25_catalog bm25vector Built-in unicode Initial release with bm25vector, bm25query, USING bm25, and Block-WeakAnd Top-K scan.

Detailed Upgrade Changes

v0.3.0 (sql/vchord_bm25--0.2.2--0.3.0.sql)

  • Added page diagnostic function: 
    CREATE FUNCTION bm25_page_inspect(index regclass, blkno INT) RETURNS TEXT;
  • Added to_bm25query(regclass, int[]) convenience overload in main/late 0.3.x.

v0.2.2 (sql/vchord_bm25--0.2.1--0.2.2.sql)

  • Added prefiltering support in Block-WeakAnd (bm25_catalog.enable_prefilter GUC, enabled by default in 0.3.0).
  • Improved MVCC visibility checking during index scans to prevent dead/filtered tuples from polluting the Top-K threshold.

v0.2.0 (sql/vchord_bm25--0.1.1--0.2.0.sql)

  • Added = and <> operators for bm25vector.
  • Added implicit cast from int[] to bm25vector (_vchord_bm25_cast_array_to_bm25vector), allowing tokenize(text, name) output (INT[]) to be assigned or passed directly wherever bm25vector is expected.

v0.1.1 (sql/vchord_bm25--0.1.0--0.1.1.sql)

  • Extracted built-in create_tokenizer / tokenize functions into the dedicated pg_tokenizer extension (tokenizer_catalog), enabling rich text analyzers, Snowball stemmers, stopwords, synonyms, HuggingFace models, jieba, and lindera.
  • Simplified to_bm25query(index_oid regclass, query_vector bm25vector) to accept a bm25vector directly.

Next-Generation Rewrite (main Branch)

  • Replaced custom bm25vector with PostgreSQL’s native tsvector (CREATE OPERATOR CLASS bm25_ops FOR TYPE tsvector USING bm25), allowing users to index to_tsvector(...) columns directly with USING bm25.
  • Added parallel index build (bm25_parallel_build_main) with external merge sort and constant maintenance memory consumption.
  • Added configurable BM25 hyperparameters (k1∈[1.2,2.0]k_1 \in [1.2, 2.0], b∈[0.0,1.0]b \in [0.0, 1.0]) via WITH (options = $$ k1 = 1.2, b = 0.75 $$).
Last modified 2026-11-03 · feat(home): compact 2x2 horizontal metric cards and vivid SQL/Bash syntax highlighting (972ccec)
Adapted from tensorchord/VectorChord-bm25, © 2024–2026 TensorChord Inc., under GNU Affero General Public License v3.0. See attribution and change history.