The initrans parameter controls the initial number transaction entry slots
in a block. Maxtrans controls the maximum number of slots allowed for each
block. Each slot consumes 23 bytes of header space and even after the
transaction is compete or the rows are deleted this space is never returned
to the block for other use. You might try setting maxtrans, the default is
255.
Kenny Gump
OCP 7.3 DBA
un2000_at_hotmail.com wrote in message <7kbmm8$u4g$1_at_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.
>
>
>Sent via Deja.com http://www.deja.com/
>Share what you know. Learn what you don't.
Received on Fri Jun 18 1999 - 06:58:45 CDT
