Quick Fixes

There are a number of very common SQL problems that are easy to identify and easy to fix.

• Are the underlying tables and indexes analyzed?
• Does the SQL already have optimizer hints?
• Do you have any Cartesian Products?
• For low volume SQLs, are there any Full Table/Partition Scans?
• Do you have 5 or more tables in a single join?
• Are you accessing a table on a remote database?
• Does your Explain Plan show an AND-EQUAL step?
• Are you performing an INSERT, UPDATE, DELETE on a table with triggers?
• Are you DELETEing rows from (or updating the primary key of) a table referenced by a foreign key?
• Are you waiting ages for an INSERT, UPDATE, DELETE that is usually quick? You could be locked out.