Home » RDBMS Server » Performance Tuning » Analysing sql query
Analysing sql query [message #65785] Thu, 23 December 2004 19:05 Go to next message
Ravikumar.V
Messages: 26
Registered: July 2004
Junior Member
when a sql query is given to u how u will analysis,

what is first step in tuning sql query.
Re: Analysing sql query [message #65793 is a reply to message #65785] Fri, 24 December 2004 01:50 Go to previous message
Milind Deshpande
Messages: 93
Registered: May 2004
Member
Hi,

I think the first step is to identify the writing of SQL. A bad written SQL will never give you good result, so if you feel that some changes are required do them.

After that identify the execution plan of the query for Index usage and Full table scan etc. My statement for Index usage doesnt mean that everytime Index scan is better than Full table scan.

You identify the Cost, Card and Bytes fetched by the query and proceed further for Tuning them.

Tuning is an art that needs a persons commonsense and expertise to identify where what is required.

Hope this helps.

Milind.
Previous Topic: whether recovery is possible when instance crash occur
Next Topic: High Invalidations for SQL Area
Goto Forum:
  


Current Time: Sun Sep 20 15:49:28 CDT 2020