pgvector 0.8.7: hnsw.ef_search against the filtered query (category == 'c3' && year >= 2022); the filter is applied AFTER the index scan
ef_search  iterative_scan  mean hits    p50 ms  filt recall
40         off                   2.0       1.1        0.181
200        off                   2.0       1.7        0.199
1000       off                  10.0      26.3        1.000
40         relaxed_order        10.0       7.9        0.621
40         strict_order         10.0       9.4        0.300