I have the following query which takes 90 seconds to finish. *JOB_MEMORY* has 45 million rows, *JOB_MEMORY_STORAGE* has 50 000 rows.
Query plan: As you can see, it is indeed using an index *JOB_MEMORY_id_desc* in a backward direction, but it is very slow. When I change ordering to *desc* in the query, the query finishes immediately and the query plan is There is also an index on *JOB_MEMORY.id*. I also tried a composite index on *(fk_id_storage, id)*, but it did not help (and was not actually used). I ran *ANALYZE* on both tables. Postgres 9.6.2, Ubuntu 14.04, 192 GB RAM, SSD, shared_buffers = 8196 MB. How can I help Postgres execute the query with *asc* ordering as fast as the one with *desc*? Thank you. -- View this message in context: http://www.postgresql-archive.org/Huge-difference-between-ASC-and-DESC-ordering-tp5947712.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com.
