Re: Oracle Commits

"akolk - gelrevision.nl" wrote:
>
> Not always true. You could be doing block cleanout .........

... Which won't be affected one way or the other by issuing commits or not. But, at least in 8.0.x, if database links are used, read-only operations can set up transactions that the user didn't realize were there. You actually have to commit or rollback every so often to clear these transactions that occur as the result of cross-database link queries.

--
Jeremiah



> dgpare wrote:

> 

> > This is in addition to Mark's advice, which is correct, but if you are just

> > running a "query" as your question states you don't  have to worry about

> > commits as you are not altering/updating data, basically you are only

> > reading the data.

> > <markp7832_at_my-deja.com> wrote in message news:89midm$32r$1_at_nnrp1.deja.com...

> > > In article <89mf2v$53$1_at_nnrp1.deja.com>,

> > >   victre_at_my-deja.com wrote:

> > > > How long does it take Oracle 8.0.5 to execute a commit?  I want to

> > > > avoid running out of resources required to run a large query by using

> > > > commits every n records but also want to minimizing the execution time

> > > > of the query by not doing more commits than necessary.

> > > >

> > > Oracle 8 uses the same fast commit logic it used with ver 7, namely, on

> > > a commit Oracle flushes the redo log buffer to disk, but allows the

> > > database writer to get around to writing the changed data whenever it

> > > gets around to it (lazy writes).  Because a commit requires writing to

> > > the redo log it is relatively expensive so you are correct in that you

> > > do not want to over commit, but I think you want to base your commit

> > > frequency based on the likelihood that another session will want to

> > > update one of the rows your process updated and how long it is

> > > acceptable for them to wait.  That and the total number of bytes worth

> > > of rollback you want to limit a transaction to using.