First, see the Oracle segment advisor which recommends indexes for rebuilding:How can I tell if my Db indexes require rebuilding
Rebuild the index when these conditions are true:And as for any other rule of thumb, there are exceptions. A large enough index might not fit into 5 levels, rebuilding an index after a mass delete might not be sensible if there's another big delete later in the batch, if the index is only range scanned etc..
- deleted entries represent 20% or more of the current entries.
- the index depth is more then 4 levels.
When an index is skewedWhat on earth do you mean by "skewed"?
parts of an index are accessed more frequently than others. As a result, disk contention may occur, creating a bottleneck in performanceWhat on earth is this related to index rebuild?
MetaLink and the docs are the "official" word from Oracle, right? When I quote my notes, people chastise me for NOT citing the docs! I can't win!Please don't just spread what you read in the metalink.
That wasn't me, I just quoted the docs . . . .What on earth do you mean by "skewed"?
Oh sure. I have my own approach, but I wanted to be "politically correct", and cite the official docs. Here are my personal notes:Didn't you ever think that the note you refered has a chance to contain some flaws?
Excellent question. The benefits of large blocksizes are demonstrated on this OTN thread where we see a demo showing 3x faster performance using a larger block size:what on earth does index block size have to do with "index rebuild"?
Sorry, I tried to do them. Please re-state them, and I'll try again!I suddenly realized that you're totally ignoring my questions.
Hey, it's way better than my Korean! English is a very confusing language.That's because my English is not natural and fluent?
Oh brother.Could you please stop posting the Robin Schumacher drivel?