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Whats happens - Space inside a data block

From: <un2000_at_hotmail.com>
Date: Thu, 17 Jun 1999 20:43:55 GMT
Message-ID: <7kbmm8$u4g$1@nnrp1.deja.com>


I would like to know what really happens when deletes and updates occur inside of a data block.
I have a table with a single extent and 2555 rows( Initrans 5, Pctused 10, Pctfree 1 - the reason being that the rows will be inserted and subsequently deleted - no updates ).
When the rows are inserted for the first time, 180 rows can be packed into each block( avg rowlen 20, db_block_size 4096, block_overhead 302). Every subsequent delete( deletes all 2555 rows - not truncate )and insert( inserts 2555 rows ) causes lesser number of rows(176) to be placed in each block. This keeps decreasing to 170 and remains stable henceforth.
I would like to know why this data space decreases and if so where does the data space go - Does the block overhead increase? If so why? Also, does an increase in the Initrans( and hence the itl slots in the row directory in the Row header )affect the data space?

Thanks.

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Share what you know. Learn what you don't. Received on Thu Jun 17 1999 - 15:43:55 CDT

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