Statistics , Statistics – its all in Statistics, if you are in ORACLE!!!

Got a call on Sat night from my boss – asking me to login immediately as our nightly job which runs for about 4:30Hrs is running for more than 6hrss and still not half way through.

My first question was – what’s changed? No one seems to know. Looked into the last analyzed time for all the tables and it showed me the FRIDAY)Friday is our weekly off. I again looked into it , nothing popped up, suddenly I see a parameter change in the gather stat execution script, we tried to take a broad-brush approach and we tried to gather histogram on all index columns...

AWR report in Oracle

This is for would be DBAs! My hair is getting grayed now - so I took the liberty to share some of my knowledge which I have gathered so far. The first step I though would be to show would be DBAs how to read AWR report.