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Reg: Index - Rebuild or Coalesce?

915396May 29 2013 — edited May 30 2013
Hi Experts,

I'm reading through the Index docs but not able to get - when to Rebuild indexes and when to Coalesce?

I agree it is written in very clear words but still it's not clear to me.
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Improper sizing or increased growth can produce index fragmentation. To eliminate or reduce fragmentation, you can rebuild or coalesce the index. But before you perform either task weigh the costs and benefits of each option and choose the one that works best for your situation.

In situations where you have B-tree index leaf blocks that can be freed up for reuse, you can merge those leaf blocks using the following statement:

ALTER INDEX vmoore COALESCE;
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Also, when and how we can realize that 'the index leaf blocks can be freed for reuse' ?

Can anybody please explain me this ?

- Ranit
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Locked on Jun 26 2013
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