# bm25 (BlackGlory's digital garden — SQLite FTS5 auxiliary function note)

## Metadata

| Field | Value |
|---|---|
| Institute | Molodetz Institute — Research & Retrieval Division |
| Subject | agent-memory-recency-tracking |
| Document type | Source Citation Card |
| Tier | 2 |
| Source title | bm25 (auxiliary function note) |
| Source URL | https://blackglory.me/notes/sqlite/SQLite3/FTS_Full-Text_Search/FTS5/Querying/Auxiliary_Functions/bm25?variant=en |
| Source type | other (personal notes/digital garden) |
| Date researched | 2026-10-09 |
| Researched by | tai (agent), model: Claude Sonnet 5, on behalf of retoor |
| Research method | Search aggregator result listing (not independently opened or quoted) |
| Confidence | Not independently verified |
| Status | Active |

## Why it's here

Surfaced by the search "boost BM25 FTS5 search ranking by recency last accessed hybrid scoring formula" as personal notes on FTS5's `bm25()` auxiliary function; closely related to the sign-convention point recorded at Tier 1 in `sqlite-org-bm25-sign-flip-commit.md`, but this specific note page was not independently opened.

## Changelog

| Date | Change |
|---|---|
| 2026-10-09 | Logged as consulted-but-not-analyzed. |