Hi, my customer does performance checks of PostgreSQL 9.5 and 10. Almost all queries on 10 are faster, but there are few queries (40 from 1000) where PostgreSQL 9.5 is significantly faster than. Unfortunately - pretty fast queries (about 20ms) are too slow now (5 sec).
attached execution plans
It looks like some cost issue, slow queries prefers Seq scan against bitmap
heap scan
Hash Cond: (f_ticketupdate_aad5jtwal0ayaax.dt_event_id =
dwh_dm_aabv5kk9rxac4lz_aaonw7nchsan2n1_aad8xhr0m_aaewg8j61ia.id)
-> Parallel Seq Scan on f_ticketupdate_aad5jtwal0ayaax
(cost=0.00..1185867.47 rows=24054847 width=8) (actual time=0.020..3741.409
rows=19243863 loops=3)
-> Hash (cost=27.35..27.35 rows=7 width=4) (actual time=0.089..0.089
rows=7 loops=3)
Buckets: 1024 Batches: 1 Memory Usage: 9kB
Regards
Pavel
pg10_regression.sql
Description: application/sql
