Index Rebuilding: The Debate
There's a fair bit of debate over the question of whether to rebuild indexes, especially on a routine basis. There are many reasons why DBAs rebuild. Some are valid; some are based upon myth or misunderstanding.
Arguments for Rebuilding
In this section, we summarize the arguments traditionally advanced to support regular rebuilding of indexes.
- Oracle B-tree indexes become unbalanced over time: One of the most common reasons advanced by proponents of frequent rebuilds is that Oracle B-tree indexes become unbalanced over time if they're subject to a heavy amount of updates and deletes. This is not true as the height between the root block and all the leaf blocks is always consistent.
- Deleted space in an index is deadwood: ...
Get Expert Indexing in Oracle Database 11g: Maximum Performance for Your Database now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
