jimandClaude Opus 5
a9bd5a4c37
The file was already tight -- freelist 0 pages, and a plain VACUUM reclaimed nothing -- so the saving had to come from schema rather than compaction. Profiled with dbstat and measured every step on copies of the live file. Three changes to Notes, applied 2026-08-07: - Rebuild as WITHOUT ROWID (-32 MB). The 5-column composite primary key was stored twice: once in the table, once in a 62 MB autoindex existing only to map key -> rowid. Keying the table b-tree on the primary key itself drops the second copy. ix_NoteBlogName01 grows 25 -> 58 MB in exchange, since a secondary index on such a table carries the whole primary key instead of a rowid; net -32 MB. - Drop Notes_idx_06e01ae3 on TimeStamp DESC (-14 MB). Barely earned its keep as a rowid index and would have cost 58 MB after the conversion, cancelling the entire exercise. The crawler's only TimeStamp filter (>= 1535778000) excludes 786 of 1,182,333 rows; Rolodex's default Notes sort carries a three-column tiebreaker forcing a full sort regardless; the reply-matching UPDATE uses ABS(TimeStamp - ?) <= 5, which no index on the column can serve. Cost is one path: Rolodex's Notes page with a date-range filter, 60 ms -> 164 ms. - Null the DatetimeCrawled placeholder (-13 MB). 1,148,077 rows stored the literal DDL default '2/12/26 12am', a backfill marker rather than a crawl time. UI-neutral: Rolodex reads the column through DateSql.Sortable, whose CASE matches neither format, so those rows already rendered as an em dash. No application code changed. The schema keeps the same tables, columns, types and constraints; WITHOUT ROWID is a storage-layout change behind the same SQL surface, and no consumer referenced rowid on Notes. Verified against all three consumers on the live file: integrity_check ok, row counts unchanged (1182333 / 22468 / 188620), journal_mode still wal, crawler INSERT OR IGNORE still dedupes, Rolodex's NoteBlogName filter still uses ix_NoteBlogName01, and exactly as many rows read as null through Sortable after the change as before it. TumblThree touches only Blogs, which is untouched. Deliberately not done: nulling Notes.DateCreated (a further -12 MB). Unlike DatetimeCrawled its value parses as a real date, so Rolodex displays and sorts by it; nulling would turn visible dates into em dashes. Note that DEFAULT '2/12/26 12am' remains on the column, so any writer inserting a note without naming it reintroduces the placeholder. Consumer-side date normalisation must stay. Co-Authored-By: Claude Opus 5 <[email protected]>