| avoiding fragmentation [message #62564] |
Thu, 29 July 2004 04:17  |
Prasad
Messages: 104
Registered: October 2000
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Senior Member |
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hi friends
i found some tables have fragmented(chained rows). i need to defragment or i want to avoid it in future .which is best way i am using oracle 7.3 in solairs.if export the table drop it and import back .is it a good one.is there any problems for integrity constraints or other constarians that realted to another table like foreign key and primary key wheter its effect the applciations give like contraints errors
or if i have to reset the storage parameters on wht basis i select the values for intial extent and maxextent.whether i have to consider the rowsize or any other criteria to be take consider
with regards
prasad
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| Re: avoiding fragmentation [message #62566 is a reply to message #62564] |
Thu, 29 July 2004 04:43  |
BhavinShah
Messages: 105
Registered: February 2004
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Senior Member |
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Hi..
Prasad
first, can u tell me how can u able to fine fragmentation?
I have one solution for that..
export the user with compress=y and then import the user..
but not forget to take a backup before doing this..
bye..
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| Re: avoiding fragmentation [message #62569 is a reply to message #62564] |
Thu, 29 July 2004 10:01 |
andrew again
Messages: 2577
Registered: March 2000
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Senior Member |
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Having chained rows is different to fragmentation. Having chained rows can be a normal condition and you should only consider trying to rectify it if they represent a reasonably large % of the rows in that table. (select table_name, CHAIN_CNT/NUM_ROWS, last_analyzed from user_tables where...). By increasing PCTFREE (from the default of 10%) on problem tables you can reduce/eliminate chained rows (assuming you don't have huge rows which couldn't fit into a batabase block without chaining).
Search google for "How to Stop Defragmenting and Start Living" for the truth about fragmentation.
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| Re: avoiding fragmentation [message #62613 is a reply to message #62564] |
Tue, 03 August 2004 01:12 |
Satheesh Babu.S
Messages: 35
Registered: July 2004
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Member |
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hi,
for chained rows you might to choose bigger block size. But generally if you want to reduce fragmentation, you can use uniform extent i.e initial=next extent.
Thanks and Regards,
Satheesh Babu.S
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