Re: PATCH: logical_work_mem and logical streaming of largein-progress transactions - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: PATCH: logical_work_mem and logical streaming of largein-progress transactions
Date
Msg-id CAA4eK1+K+_6UT_WSYGsgodS96mYZ__Bs_69U5J_JwckK+sE9Ag@mail.gmail.com
Whole thread Raw
In response to Re: PATCH: logical_work_mem and logical streaming of largein-progress transactions  (Dilip Kumar <dilipbalaut@gmail.com>)
Responses Re: PATCH: logical_work_mem and logical streaming of largein-progress transactions
List pgsql-hackers
On Mon, Jun 22, 2020 at 4:41 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
>
> On Mon, Jun 22, 2020 at 4:26 PM Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > On Thu, Jun 18, 2020 at 9:02 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> > >
> > > Yes, I have made the changes.  Basically, now I am only using the
> > > XLOG_XACT_INVALIDATIONS for generating all the invalidation messages.
> > > So whenever we are getting the new set of XLOG_XACT_INVALIDATIONS, we
> > > are directly appending it to the txn->invalidations.  I have tested
> > > the XLOG_INVALIDATIONS part but while sending this mail I realized
> > > that we could write some automated test for the same.
> > >
> >
> > Can you share how you have tested it?
>
> I just ran create index concurrently and decoded the changes.
>

Hmm, I think that won't reproduce the exact problem.  What I wanted
was to run another command after "create index concurrently" which
depends on that and see if the decoding fails by removing the
XLOG_INVALIDATIONS code.  Once you get some failure, you can apply the
0002 patch and see if the test is passed?

>
> > @@ -2012,8 +2014,6 @@ ReorderBufferForget(ReorderBuffer *rb,
> > TransactionId xid, XLogRecPtr lsn)
> >   if (txn->base_snapshot != NULL && txn->ninvalidations > 0)
> >   ReorderBufferImmediateInvalidation(rb, txn->ninvalidations,
> >      txn->invalidations);
> > - else
> > - Assert(txn->ninvalidations == 0);
> >
> > Why this Assert is removed?
>
> Even if the base_snapshot is NULL, now we are collecting the
> txn->invalidation.
>

But there doesn't seem to be any check even before this patch which
directly prohibits accumulating invalidations in DecodeCommit.  We
have check for base_snapshot in ReorderBufferCommit.  Did you get any
failure with that check?

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com



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