On 2018-11-29 14:27:50 +0100, Dmitry Dolgov wrote:
> > On Fri, Sep 21, 2018 at 5:52 AM Andrey Lepikhov <a.lepikhov@postgrespro.ru> wrote:
> >
> > The v6 version of quick vacuum, which utilizes the amtargetdelete()
> > interface for retail indextuple deletion.
> > Now it is more simple and laconic.
> > It must be applied after Retail-IndexTuple-Deletion-Access-Method.patch.
> >
> > BENCHMARKS:
> > -----------
> >
> > Initial script:
> > pgbench -i -s $scale # initial DB generation
> > "CREATE INDEX pgbench_accounts_ext ON public.pgbench_accounts USING
> > btree (abalance);" # additional index
> >
> > Comparison with lazy vacuum:
> >
> > script:
> > "DELETE FROM pgbench_accounts WHERE (random() < $factor);" # delete a
> > part of tuples for cleaning strategies comparison
> > "VACUUM pgbench_accounts;" # check time of vacuum process by bash 'date
> > +%s%N | cut -b1-13' command
> >
> > Results:
> > | $scale=10 | $scale=100 |
> > $factor| QVAC | LVAC | QVAC | LVAC |
> > 1E-6 | - | - | 284 | 979 |
> > 1E-5 | 78 | 144 | 288 | 1423 |
> > 1E-4 | 72 | 280 | 388 | 3304 |
> > 1E-3 | 189 | 609 | 2294 | 6029 |
> > 1E-2 | 443 | 783 | 54232| 67884|
> > 1E-1 | 1593 | 1237 | 83092| 86104|
> >
> > where QVAC - forced use of quick vacuum; LVAC - use lazy vacuum for
> > index cleanup. $factor corresponds a number of vacuumed tuples. For
> > example, $scale=10, $factor=1E-1 -> 100000 tuples vacuumed. Time
> > measured in ms.
> >
> > So, quick strategy can be used in a vacuum process effectively up to
> > 1-2% of DEAD tuples in a relation.
>
> Hi,
>
> Unfortunately, this patch doesn't compile anymore:
>
> index.c: In function ‘htid2IndexDatum’:
> index.c:4172:2: error: too few arguments to function ‘MakeSingleTupleTableSlot’
> TupleTableSlot *slot = MakeSingleTupleTableSlot(RelationGetDescr(hrel));
> ^
>
> Also I'm a bit confused about the current status of collaboration between this
> patch and [1], one is tightly depends on another or not? Does it makes sense
> to have only one corresponding CF item then? For now I'll move this one to
> the next CF.
>
> [1]:
https://www.postgresql.org/message-id/flat/CAH2-WzkVb0Kom%3DR%2B88fDFb%3DJSxZMFvbHVC6Mn9LJ2n%3DX%3DkS-Uw%40mail.gmail.com
Given this patch has not been updated since Dmitry's message above, I'm
marking this as returned with feedback.
Greetings,
Andres Freund
