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how to find index to rebuilt [message #525435]

Mon, 03 October 2011 02:11

sathish16787
Messages: 56
Registered: September 2011
Location: mumbai

Member

i am trying to find the index want to rebuild or not
for that i have analysed that index after that i dont know how to calculate the ration could any one help me steps to do calculate the following ratio

Run the ANALYZE INDEX command on the index to validate its structure and then calculate the ratio of LF_BLK_LEN/LF_BLK_LEN+BR_BLK_LEN and if it isn?t near 1.0 (i.e. greater than 0.7 or so) then the index should be rebuilt. Or if the ratio BR_BLK_LEN/ LF_BLK_LEN+BR_BLK_LEN is nearing 0.3.

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Re: how to find index to rebuilt [message #525442 is a reply to message #525435]

Mon, 03 October 2011 02:47

Michel Cadot
Messages: 68737
Registered: March 2007
Location: Saint-Maur, France, https...

Senior Member
Account Moderator

Quote:

i am trying to find the index want to rebuild or not

I have the answer: none.

Quote:

Run the ANALYZE INDEX command on the index to validate its structure and then calculate the ratio of LF_BLK_LEN/LF_BLK_LEN+BR_BLK_LEN and if it isn?t near 1.0 (i.e. greater than 0.7 or so) then the index should be rebuilt. Or if the ratio BR_BLK_LEN/ LF_BLK_LEN+BR_BLK_LEN is nearing 0.3

Bullshit.

Regards
Michel

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Re: how to find index to rebuilt [message #525693 is a reply to message #525435]

Tue, 04 October 2011 11:40

LNossov
Messages: 318
Registered: July 2011
Location: Germany

Senior Member

Your question isn't so easy. There are some different approaches to estimate the indexes. It is also very important to know, what kind of index you have: normal, iot, bitmap. Answer please firstly the following 2 questions:

- are there optimizer statistics for this index?
- what kind of index is it?

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