Good morning all,
I am looking for lists of guidelines or tips for writing efficient sql queries to help to increase application performance and query tunning, and the reasons of using them. These tips including using NOT EXISTS instead of NOT IN and never use NOT on an indexed column etc. If you have the lists, can you share with me? You can send them to email@example.com. Or can you send me a link where I can find them?
select executions, disk_reads, buffer_gets, sql_text from v$sql where disk_reads >100 order by disk_reads ;
take the sql statement which has the most disk reads..
try to get the execution path by using the explain plan ...
see whether the table
how many rows
if there is index will it improve the performance ...
try doing it within days you will catch up ...
If you have Metalink acess , pl search for SQL Tuning , you see very good documents ..
May be the above link will help you
Read the performance and tuning manual.
Thank you, thank you, thank you all!