Re: BAMIMA:Bam Buffer

Jim wrote: -

"It is actually easier to use bind variables"

I wish this were always true! but not it isn't always and not due to Oracle limitations or anything - just due to intransigent or stubborn developers or development managers.

Bind vars is the way to go if you can force that change. cursor sharing is the dba's best response to stupid development decisions. Perhaps Ray could use cursor sharing = force to demonstrate the benefits in order to add weight to the move to bind variables but it could backfire - management will just say "ah well that fixes it just as good as bind vars so we'll not bother changing the code" :-). Not that I've been down that road myself obviously - all just theoretical management decision bashing :-))).

Andy

"Jim Kennedy" <kennedy-downwithspammersfamily_at_attbi.net> wrote in message news:0IEEb.603343$Fm2.547536_at_attbi_s04...
> It is actually easier to use bind variables and a LOT more scalable.
Maybe
> the developers aren't competent.
> Jim
> "Ray Teale" <ray_at_BLAHholly.com.au> wrote in message
> news:bXzEb.267$g21.6776_at_nnrp1.ozemail.com.au...
> > Thanks for all your input.
> >
> > It is definitely a problem with fragmentation caused by the app
developers
> > using dynamic sql without bind variables.
> >
> > A more thorough seach of the sqlarea showed lots of examples of the same
> sql
> > statement with different constant values.
> >
> > Guess I'll have to convince the app developers to rewrite some of this.
> > CURSOR_SHARING=FORCE may work as a temporary fix, but I'm not game to
try
> it
> > on the production system.
> >
> > Regards
> >
> > Ray
> >
> >
> > <sybrandb_at_yahoo.com> wrote in message
> > news:a1d154f4.0312190059.96b97b7_at_posting.google.com...
> > > "Ray Teale" <ray_at_BLAHholly.com.au> wrote in message
> > news:<DruEb.74$g21.2793_at_nnrp1.ozemail.com.au>...
> > > > Version : 8.1.7.0.0
> > > > Sun Solaris 2.8
> > > >
> > > > I'm getting the old BAMIMA:Bam Buffer error regularly on my
database.
> > > > I have tried pinning packages to no avail. I have also increased
the
> > size
> > > > of the shared pool size and it is now three times the initial size
> > (About
> > > > 300M). All that is happening is that it is taking longer between
> > failures.
> > > >
> > > > I suspect that the application which is using the database may have
a
> > lot of
> > > > dynamic SQL. I'm wondering if this might be an issue as the dynamic
> > > > statements do not have bind variables.
> > > >
> > > > I'm confused about the error because I thought select statements
would
> > be
> > > > aged out rather than the shared pool run out of memory.
> > > >
> > > > Can anybody shed light?
> > > >
> > > > Regards
> > > >
> > > > Rau
> > >
> > >
> > > Dynamic sql will definitely exhaust the sql area. For statements
> > > without bind variables, each statement will be loaded in the sqlarea.
> > > Eventually they will be aged out, but if someone executes the
> > > statement again it will be reloaded.
> > > Such scenario easily results in fragmentation of the shared pool, as
> > > likely not all the statements have the same statement length. In which
> > > you are left with ora-4031.
> > > As far as I know, apart from throwing the app out of the window/start
> > > using bind variables, the only other method to alleviate the problem
> > > is to make sure the cursor_sharing parameter is set to FORCE. This
> > > will have Oracle set up bind variables and translate the hardcoded
> > > literals in the statement into bind variables.
> > >
> > > Regards
> > >
> > > Sybrand Bakker
> > > Senior Oracle DBA
> >
> >

>
> Received on Fri Dec 19 2003 - 10:16:42 CST