consistent gets > segment size during FTS [message #281347] |
Fri, 16 November 2007 08:28 ![Go to next message Go to next message](/forum/theme/orafaq/images/down.png) |
mlobel1
Messages: 2 Registered: November 2007
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Junior Member |
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Hi everybody,
Why during a FTS the "consistent gets" are larger than the number of blocks in my table ? I will explain :
I created a table with 2 fields n number and c varchar2(50)
I inserted 58336 lines with n=1 and 32 lines with n=2
segment size is 512 blocks (blocksize is 8 kb)
I created a non unique index on n
My goal was testing execution plans issuing select *, select * where n=1 and select * where n=2 in these cases :
1- without any stats
2- with stats but no histograms
3- with stats and histograms
All the execution plans I obtained are the plans I expected.BUT :
I can not explain why tkprof ouputs 4392 consistent gets during a FTS issuing a select * from my_table knowing the segment size fot the table is 512 blocks.
Does anyone can explain me that behaviour ?
Thanks !
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Attachment: FTS.xls
(Size: 14.00KB, Downloaded 1255 times)
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