sqlANYsqlitecreate-index
sql
CREATE INDEX idx_notes_user_id_created_at ON notes (user_id, created_at DESC);A compact way to speed up per-user timelines or history screens.
SQLite Indexes and Query Planner
SQLite CREATE INDEX patterns, expression and partial indexes, EXPLAIN QUERY PLAN, and lightweight performance tuning.
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SQLite index creation
Practical CREATE INDEX examples for apps and embedded databases.
sqlANYsqliteexpression-index
sql
CREATE INDEX idx_users_lower_email ON users (lower(email));Helpful when the query uses the same expression in predicates.
sqlANYsqlitepartial-index
sql
CREATE INDEX idx_tasks_open_due_at ON tasks (due_at) WHERE completed_at IS NULL;A smaller index can be more efficient when only open tasks matter to the hot path.
Planner tools
Validate the actual plan chosen by SQLite.
sqlANYsqliteexplain-query-plan
sql
EXPLAIN QUERY PLAN
SELECT id, created_at
FROM notes
WHERE user_id = 42
ORDER BY created_at DESC
LIMIT 20;SQLite reports whether it scans a table, searches with an index, or can use a covering index optimization.
sqlANYsqliteanalyzestatistics
sql
ANALYZE;Statistics can improve plan selection in nontrivial schemas.
bashANYsqlitecliexpert
bash
sqlite3 app.db ".expert"The SQLite CLI includes tools that can help surface candidate indexes for sample queries.
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Use PostgreSQL B-tree, GIN, GiST, BRIN, partial indexes, expression indexes, and concurrent builds effectively.