*Unreleased*

With approximate indexes, queries with filtering can return less results (due to post-filtering).

Starting with 0.8.0, you can enable iterative index scans. If too few results from the initial scan match the filters, the scan will resume until enough results are found (or it reaches`hnsw.max_scan_tuples` or`ivfflat.max_probes`). This can significantly improve recall.

With approximate indexes, queries with filtering can return less results (due to post-filtering). Starting with 0.8.0, you can enable iterative index scans. If too few results from the initial scan match the filters, the scan will resume until enough results are found (or it reaches`hnsw.max_scan_tuples` or`ivfflat.max_probes`). This can significantly improve recall.

There are two modes for iterative scans: strict and relaxed.

SETivfflat.iterative_scan= relaxed_order;

Note: IVFFlat only supports relaxed ordering for iterative scans

With relaxed ordering, you can use a[materialized CTE](https://www.postgresql.org/docs/current/queries-with.html#QUERIES-WITH-CTE-MATERIALIZATION) to get strict ordering