Re: InitTrans parameter

From: Thomas Kyte <tkyte_at_us.oracle.com>
Date: 1997/10/03
Message-ID: <3436fb54.3385217@newshost>#1/1

On Fri, 03 Oct 1997 10:25:23 -0700, Appala <charyunv_at_boat.bt.com> wrote:

>arpege wrote:
>>
>> What is the inittrans parameter used for ? From what I've read, it books
>> some space in the block header of an extent of a table ... But what is
>> it exactly used for ??
>
>Inittrans is the minimum number of transactions that access the
>datablocks. 23 Bytes (I remember) per Transaction entry is stored in the
>datablocks of the corresponding segments
>
>Generally for tables inittrans will be 1 and for indexes 2.
>
>Low inittrans will cause users to wait, if many users are accessing same
>datablock concurrently.

Not exactly. Low MAXtrans could cause people to wait. INITrans specifies the fixed overhead on a block for transactions (the number of preallocated transaction entries). Oracle will allocate on the block more transaction entries dynamically upto MAXtrans (or until the block is completely full).

So MaxTrans is the one to watch for if you have to watch it. Its a function of the block size and is OS dependent.

Thomas Kyte
tkyte_at_us.oracle.com
Oracle Government
Bethesda MD

http://govt.us.oracle.com/ -- downloadable utilities

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Opinions are mine and do not necessarily reflect those of Oracle Corporation Received on Fri Oct 03 1997 - 00:00:00 CDT