RE: Postgres DB Slowness

From: Ron <ronljohnsonjr@gmail.com>
Sent: Thursday, August 22, 2019 4:26 PM
To: pgsql-admin@lists.postgresql.org
Subject: Re: Postgres DB Slowness

On 8/22/19 9:04 AM, soumik.bhattacharjee@kpn.com wrote:

Hello Members,

 

We have the below PostgreSQL database recently migrated from Oracle.

 

The postgres DB parameters are attached here.

 

# DB Version: 10

# OS Type: Linux

# Total Memory (RAM): 30 GB

#CPU

nproc --all

2

 

There is huge slowness in the database now with any queries.

 

Oracle - Select * from TABLENAME- in takes  0.009 milliseconds

PostgreSQL - Same query takes more than 2 minutes.

Have you validated that the Postgres server has the same indexes?

If so, did you ANALYZE all the tables?

Yes Ron, we migrated from Oracle as per same structure and indexes.

 

I did the analyze for 2-3 tables now as per my SQL query I wrote and also ran for one particular table below –

 

VACUUM (FULL,ANALYZE) table_name.

What does the query plan for that query look like?

What's the table definition?

Is the hardware comparable?  (Might it be a SAN or VM issue?)