Re: Size of rollback segments for a single transaction

not sure about this but does the rollback not work on 'block' instead of 'table & columns '?

If I remember, the rollback will keep a copy of each 'database blocks' that has been altered by the user.

this can have serious implication since a lot of block would be keeped in the sement when every row of a table are altered.

This is why you can have error messages when the rollback segment is to small

also, the solution will be dependant on HOW you are updating every row . a program ? PL/SQL ? SQL+ ?

In article <35071406.5DC9_at_deere.com>, "John P. Higgins" <jh33378nospam_at_deere.com> wrote:
>Olivier wrote:
>>
>> I am updating every row of a single column in a table containing many rows
>> and many columns. What is the minimal size of the rollback segment for that
>> transaction ? Will the rollback segment have to store all data contained in
>> the table or just the values actually changed by the transaction?
>>
>> Thanks Olivier.
>The rollback segment must store the values from every column that is
>named in the update command. If a table has 10 columns and you refer to
>5 of them in the update command but only 1 column gets a new value, the
>rollback must record the before values of the 5 referenced columns.

Nicolas

Nissakid_at_planete.net
Microsoft Certified Product Specialist
AUI Member

The above represents my own opinion not my employer's and does not necessarily constitute the official policy of my employer. Any opinion developed through this account represent a private conversation. Received on Thu Mar 12 1998 - 00:00:00 CST