Re: Performance issue post upgrade on Version 13 - Incorrect Estimation Cost choosing Hash Aggregate-Nested Left Loop Join

On Tue, Mar 22, 2022 at 12:57:10PM +0000, Prajna Shetty wrote:
> 1.      We have performed Vacuum/Analyze/Reindex post Upgrade.
> 2.      Tweaked work_mem so it does not spill to Disk. We can Disk Usage But it is still using Hash Aggregate and
camedown from 5 minutes to 20 seconds. (Expected ~5 seconds). Attached plan after modifying work_mem
 
> 3.      Disabled Seqcan/ nestedloop
> 4.      Tweaked random_page_cost/seq_page_cost
> 5.      Set default_statistics_target=1000 and then run vacuum(analyze,verbose) on selected tables.
> 6.      We have also tested performance by increasing resources up to 4 vCPU and 32 GB RAM.

Would you provide your current settings ?
https://wiki.postgresql.org/wiki/Server_Configuration