Postgresql Upgrade from 10 to 14

On 4/8/23 18:03, thayanban thay wrote:

  Hi Team,

I need some help or suggestions for the below issue. Please provide
answers what to do now. We re in critical position to handle the issue.

Issue: We upgraded postgresql from 10 to 14 version, post to the upgrade
, queries are running very slower than normal expected time. As well as
the queries are not getting completed . We did vacuum analyze, index
recreation and analyze statements etc but no luck still the job queries
are running slower like 10hrs , 14hrs . So please help what we need to
do to fix the issue.-

Actually we have spark scala application that will use JDBC driver to
make connection to the postgresql and then execute the queries. Before
upgrade the same application used to complete in very lesser time like
10mts but now its taking 14hrs and not getting completed.

Not sure why upgrade making slower in performance. Previously the job
used to complete in lesser time.

Please advise and provide suggestion what inorder to do fix the issue.
Kindly help and waiting for good reply with exact solutions

More information needed:

1) OS and version?

2) Where is server hosted, on your machines or a service?

3) The hardware specifications for the machine?

4) How was the upgrade done?

5) An example of a slow query with the output of EXPLAIN <the_query>

6) What version of the JDBC driver?

--
Adrian Klaver
adrian.klaver@aklaver.com

thayanban thay <thayanban96@gmail.com> writes:

Issue: We upgraded postgresql from 10 to 14 version, post to the upgrade ,
queries are running very slower than normal expected time. As well as the
queries are not getting completed . We did vacuum analyze, index recreation
and analyze statements etc but no luck still the job queries are running
slower like 10hrs , 14hrs . So please help what we need to do to fix the
issue.

You are unlikely to get any useful advice when you've provided no details.
You need to identify which query or queries has gotten slower, and post
the problem queries along with related table schemas and EXPLAIN output.
See

https://wiki.postgresql.org/wiki/Slow_Query_Questions

for some advice about how to ask answerable performance questions.

Just a shot in the dark: some people upgrading past v12 have found that
queries using WITH got slower because WITH clauses can now be inlined
whereas the previous behavior was always the equivalent of WITH ... AS
MATERIALIZED. The new behavior is usually better but we have seen
cases where it loses. Your issue could be something else entirely
though.

regards, tom lane