Vishwa Kalyankar schrieb am 10.07.2020 um 08:50:
> Previously we are running postgresql-10with postgis 2.5.3 and now we
> are updated to postgresql-12 and postgis-3.0.1, and in postgresql-10
> one query is taking 20 sec and same query is taking upto 80 sec.
Most of the slowdowns I have seen when upgrading to Postgres 12 were caused by JITting, which seems to kick in more often than not on queries that don't profit from it.
Try to disable jit (set jit=off) and re-run your query