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Database / SQLite Interview questions

What is the difference between VACUUM and ANALYZE in SQLite?

Both are maintenance commands, but they address different things: VACUUM reclaims unused disk space left behind by deletes/updates by rebuilding the database file; ANALYZE gathers statistics about table/index contents that SQLite's query planner uses to make better decisions about which index to use for a given query.

VACUUMANALYZE
Rebuilds the database file, reclaiming space from deleted rows. Gathers statistics for the query planner; doesn't change file size.
Can take significant time and requires free disk space to run. Typically fast, just scans a sample of data for statistics.
Run occasionally after significant deletes. Run after significant data changes so the planner's statistics stay current.
VACUUM;
ANALYZE;

What does VACUUM do?
What does ANALYZE provide that VACUUM does not?

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