On Tue, 2022-11-29 at 19:09 +0100, Alvaro Herrera wrote:
> On 2022-Nov-29, Mladen Gogala wrote:
>
> > Hmmm, I think I will run pgbench with and without JIT on and see
> > the
> > difference.
>
> I doubt you'll notice anything, because the pgbench queries will be
On 11/29/22 03:36, Alvaro Herrera wrote:
On 2022-Nov-28, Mladen Gogala wrote:
As for JIT, I've recently asked that question myself. I was told that
PostgreSQL with LLVM enabled performs approximately 25% better than without
it.
Hmm, actually, normally you're better off turning JIT off
On 11/29/22 03:31, Alvaro Herrera wrote:
On 2022-Nov-28, Mladen Gogala wrote:
You'll probably be glad to learn that we have hints now.
What hints are you talking about? As I understand, we still don't have
Oracle-style query hints.
https://github.com/ossc-db/pg_hint_plan
--
Mladen Gogala
, I was looking
for a generic settings to install via Ansible so I don't have the
numbers, only the feeling. One way of quantifying the difference would
be to run pgbench with and without JIT.
PS:
I am still an Oracle DBA, just as you wrote in the paper.
--
Mladen Gogala
Database Consultant
g and try optimizing
them.
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bly help you with that schema. Other than that, do you
have a SQL causing all this ruckus and a detailed explain plan ("explain
(analyze,costs,buffers)") for the SQL using most of the time? You can
analyze the log file with PgBadger to get the queries consuming the most
time.
--
lse encountered this problem?
When I say "XA transactions are much slower", I mean that commit and/or
rollback take much longer. The SQL execution takes the same and the
plans are identical to the 13.5 version. The application code is the
same, using IBM WebSphere 9.0.4.
Regards
--
ut to use much larger machine
with the NVME disks, which can handle the necesary I/O. Are there any
plans to allow global indexes? I am aware that this is not a small
change but is the only real advantage that Oracle holds over PostgreSQL.
Regards
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Mladen Gogala
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Tel: (347) 321-1217
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at 19 miles a second, so it's reckoned,The
sun that is the source of all our power. So, several hours is relative.
Each object has its relative time so it's not possible to conclude
whether several hours is a long time or not.
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https
of action is to completely rewrite the queries,
probably using CTE and temporary tables. May the Force be with you.
Regards
--
Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com
TT.TEST1_UQ) violated
Elapsed: 00:00:00.033
Oracle is rejecting the same row twice, regardless of whether it
contains NULL values or not. As in Postgres, the resulting index can be
used for searches. However, Oracle index is not a function-based index
because it doesn't contain the coalesce func
a
query that can be well calculated in parallel, then positive effect of
JIT is less.
Regards
Pavel
Thanks Pavel, you answered my question. I'll wait with the upgrade.
Regards
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
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large databases and CREATE INDEX CONCURRENTLY and
REINDEX CONCURRENTLY fixes in 13.5 are highly desired but not at the
cost of the overall application performance.
Regards
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
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an
in-memory queue manager which is, generally speaking, very fast.
Applications usually do stupid things. I've seen GUI doing "SELECT FOR
UPDATE". And then the operator decided to have lunch. I'll leave the
rest to your imagination.
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Mladen Gogala
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to this discussion, I discovered Bloom extension. Bloom
indexes are phenomenally useful. I apologize for the digression.
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
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they did fill the file system.
As for the "tracing vs. sampling" debate, Oracle has both.
V$ACTIVE_SESSION_HISTORY is a sampling view. Sampling views are more
practical, especially when there are pooled connections. Personally, I
would prefer sampling.
--
Mladen Gogala
Datab
On 10/6/21 16:32, Dirschel, Steve wrote:
postgres=# explain (analyze) delete from t; Delete on t
I would try explain (analyze, timing, buffers). That would also give you
the timing of each step so you can figure which one takes the longes.
Regards
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Mladen Gogala
Database Consultant
. They may use strace for you.
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Mladen Gogala
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rocesses are doing using strace -e trace=file and,
for good measure, 'perf top".
Regards
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
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for
generations to come.
Or not. Laurenz will probably tell you that we don't top-post in
Postgres community. He's good with rules, regulations and the way things
are done in Postgres community.
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Mladen Gogala
Database Consultant
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ay not see Jeff Holt
again on this group so I am providing my opinion instead. At least I
would, in Jeff's place, be reluctant to return to this group.
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Mladen Gogala
Database Consultant
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. As for Jeff, I don't need to 'champion
him'. He did that all by himself. In his place, I would simply ignore
both this topic and you, Mr. Postgres Community.
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
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nsulting jobs in big banks and for a decent money, you might just take
Oracle people seriously. Have you ever wondered why Oracle has so many
customers despite the fact that it's so freakishly expensive?
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
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, PostgreSQL now has query hints.
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com
Brian Kernighan or Dennis Ritchie.
And yes, those two have allegedly also written a book.
Regards
--
Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com
ms (00:03.115)
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Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com
index. It uses the index I expect and it's much faster.
Here's <https://explain.depesz.com/s/KBgG> a plan if we disable index
scans. It uses both indexes and is much faster.
--
Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com
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