How to find Top Hard Parsing SQL Statements?

Posted on by Ahmed Abdel Fattah

Background:A hard parse occurs when a SQL statement has to be loaded into the shared pool. In this case, the Oracle Server has to allocate memory in the shared pool and parse the statement.A hard parse is a heavy process in terms of resources (CPU & Memory), and we should avoid whenever possible.Excessive hard parsing … Continue reading How to find Top Hard Parsing SQL Statements?

Oracle Database Performance Issue: High waits for “PX Deq: Slave Session Stats”

Posted on by Ahmed Abdel Fattah

I had a customer who complains about performance issues on one of the oracle production database. Environment Oracle Database 12c R1 (12.1.0.2) on Linux with Oracle RAC (two nodes). To start with, I collected some AWR reports around the complain time, and I found the top wait events (most of the time) as follows: So, … Continue reading Oracle Database Performance Issue: High waits for “PX Deq: Slave Session Stats”