pgsql-performance@lists.postgresql.org

ing? My understanding from the documentation is that it does not need autoanalyze stats. Thanks Thank you From: Justin Pryzby Sent: Wednesday, February 27, 2019 11:15 AM To: Fd Habash Cc: pgsql-performa...@postgresql.org Subject: Re: What is pg_stat_user_tables Showing NULL for last_aut

What is pg_stat_user_tables Showing NULL for last_autoanalyze & last_autovacuum

I have been able to locate four google search results with the same inquiry. What’ve been able to understand is … 1. If auto-vaccum is working as expected, stats collector does not nullify these values as part of a startup sequence or regular Maitenance. If a relation gets auto[vacuumed|analyze

How Do You Associate a Query With its Invoking Procedure?

In API function may invoke 10 queries. Ideally, I would like to know what queries are invoked by it and how long each took. I’m using pg_stat_statement. I can see the API function statement, but how do I deterministically identify all queries invoked by it? Thank you

RE: Select count(*) on a 2B Rows Tables Takes ~20 Hours

Just checked metrics while the count was running … Read latency < 3.5 ms Write latency < 4 ms Read throughput ~ 40 MB/sec with sporadic peaks at 100 Read IOPS ~ 5000 QDepth < 3 Thank you From: Tom Lane Sent: Thursday, September 13, 2018 2:12 PM To: Fd Habash

Select count(*) on a 2B Rows Tables Takes ~20 Hours

Based on my research in the forums and Google , it is described in multiple places that ‘select count(*)’ is expected to be slow in Postgres because of the MVCC controls imposed upon the query leading a table scan. Also, the elapsed time increase linearly with table size. However, I do not kno

RE: Guideline To Resolve LWLock:SubtransControlLock

Jeremy … In your statement, what constitutes ‘heavy use of exception blocks’? Thanks I have seen applications grind to a halt on SubtransControlLock when they make heavy use of exception blocks in plpgsql code; in fact it's pretty straightforward to demonstrate this behavior with pgbench on

RE: Guideline To Resolve LWLock:SubtransControlLock

Thanks, Jeremy … “ That said... FWIW, Aurora PostgreSQL version 9.6.3 uses parent/child transaction relationships pretty much the same way that community PostgreSQL 9.6.3 does …” This is why I posted here first. This particular wait state did not appear to be Aurora specific and was not listed

RE: Simple Query Elapsed Time ~ 3 hrs Using Bitmap Index/Heap Scan

Indexes are being redone as per these insights. Appreciate the great support. Thank you From: Matthew Hall Sent: Tuesday, June 5, 2018 10:42 AM To: Fred Habash Cc: pgsql-performance@lists.postgresql.org Subject: Re: Simple Query Elapsed Time ~ 3 hrs Using Bitmap Index/Heap Scan