Re: Transaction size limitation for serializable isolation level?

Hi.
Oracle does require some extra memory for serializable transactions, and this comes from the configurable per-table memory you can adjust. If the DBMS runs out of this memory during a transaction, you will get the 8077 error, even if you're the only user logged in. The Oracle documentation would be better if it was explicit about that.

     You should also read deeply into what Oracle calls serializable and how it implements it. Please post what you want to achieve by setting the serializable isolation level. It may be that you aren't getting what you expect, and we can post alternatives that will be more reliable and understandable. Joe Weinstein at BEA

Lusiana Lusiana wrote:

> Hi All,
>
> Our system configuration is Oracle 8.1.6 on Solaris 5.8 with servlet/jsp
> using
> Tomcat as client. Transaction isolation level is set to serializable.
>
> We have some long transactions, and we have been getting 'ORA-08177: Cannot
> serialize access for this
> transaction' for these.
> The error were also experienced when there's only one user on the database
> (ie.one transaction).
> Redoing the transaction didn't help.
>
> We're converting the isolation level to read commited.
> The reason being:
> - We ran out of ideas on how to fix the problem. One of the things we tried
> was modifying some parameters, eg. INITRANS, to no avail.
> - Documentation mentions that serializable isolation level is suitable for
> short transactions. I understand this will be the case for multi user
> environment, but to me this still doesn't explain the reason why we get the
> error when there's only one user/transaction.
>
> However, I'm still very curious why we were getting the errors.
> What are the causes of 'ORA-08177' other than 'when a serializable
> transaction tries to update or delete data modified by a transaction that
> commits after the serializable transaction began'?
>
> Any ideas?
>
> Thanks,
> Lucy
>
>
>
Received on Sun Apr 18 2004 - 10:19:11 CDT