Re: PCTFREE and INITTRANS

On tables that are queried frequently and not updated (inserts are slightly ok) I use a pctfree of 5. I do not use anything less than a 5 because I know that there will be chaining if I do (for some reason even if the row is not going to be updated)

On the initrans - you must ask yourself what are the chances that multiple request will hit the particular block of data at the exact same time. The initrans parameter is just how many trans handles to default in the data block. If you set your initrans to 1 and two people use the block at the same time, Oracle will add another upto the maxtrans value.

If the chances are low that the block will be accessed by two or more (for update) then you will not need to adjust the initrans.

Thanks,
Bryan Lenihan (e-mail: bryanle_at_lenisoft.com) Certified Oracle DBA
Lenihan Software and Consulting

John Vernes wrote in message <6l9pa9$1os$2_at_news.worldonline.nl>...
>Our biggest tables (40 and 20 million records) and in our application are
>used very frequently for querrying. We have allready set thePCTFREE to 10
>and INITTRANS is still set to 1.
>
>Those tables are very high on queries and very low on updates/deletes and
>somethings large batches of inserts.
>
>What problems could I encounter when I would set the PCTFREE extremely
>low???
>For instance 2 percent (<= Muchos data in data block)
>
>Would it be advisable to set the INITTRANS higher than 1??
>I ask this, because of the huge amount of data (40M records) and the
chanche
>of
>needing to have more transactions on the same block.
>
>Thanxs and Greetz
>
>John
>
>
Received on Sat Jun 06 1998 - 01:24:06 CDT