I was looking for an old posting on the Oracle newsgroup recently, when I found a set of posts that talked about measuring the effectiveness of rebuilding some indexes.
I had contributed by pointing to my website where I have a script that demonstrates how to get some detailed information about how well the space in an index is used, and Joel Garry had responded with some results from a production instance.
The full thread starts at this URL
But for a quick summary of the conversation I had with Joel, you could go to each of these posts in turn:
- My comments about doing a tree dump of an index
- Introducing my “leaf block scan” code:
- Joel’s repsonse after using the “leaf block scan” code
- My analysis of Joel’s output
- Joel’s response to my analysis
For other notes I’ve written about index rebuilds: