Intermediate SQL Color Coded SQL, UNIX and Database Essays

23May/101

ORACLE 11g SQL Plan Management or yet another way why ORACLE may not use your index. Part 1

One of our developers called me recently and said that they had an interesting problem on their hands.

The essence of a problem was that the schema upgrade script misfired and did not create a very important index on one of the largest tables. As a result, critical queries that were supposed to hit that index were now doing full table scans and dragging on for minutes.

The weird thing was that a developer, realizing her mistake, connected to the schema and created the index manually. Yet even after that was done, target queries still full table scanned the table, completely ignoring the index.