partial index
Index only rows that satisfy a predicate.
Use this when A frequently queried subset is small compared with the whole table.
without the term
“Our jobs table has millions of finished rows but we only ever query the few pending ones. Can we speed up finding pending jobs without indexing all the old stuff?”
with the term · How do you ask a model for partial index?
Evaluate a partial index for pending jobs. Check that the actual query uses it and compare its size with a full index.
What is partial index?
A partial index limits its contents to a condition, such as rows whose status is pending.
Why does partial index matter when vibe coding?
A full-table index may do unnecessary maintenance for rows the query never needs.
How do you do partial index?
Choose the subset and verify that the planner can match the query to its predicate.
What goes wrong with partial index?
The query condition does not imply the index predicate, so the index is unusable.