Re: Patch for fast gin cache performance improvement

From: "Etsuro Fujita" <fujita(dot)etsuro(at)lab(dot)ntt(dot)co(dot)jp>
To: "'Ian Link'" <ian(at)ilink(dot)io>, "'pgsql-hackers'" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Patch for fast gin cache performance improvement
Date: 2013-09-27 09:24:43
Message-ID: 004001cebb63$669f85d0$33de9170$
Views: Raw Message | Whole Thread | Download mbox | Resend email
Lists: pgsql-hackers

I wrote:
> I had a look over this patch. I think this patch is interesting and very
> Here are my review points:

> 8. I think there are no issues in this patch. However, I have one question:
> how this patch works in the case where gin_fast_limit/fast_cache_size = 0? In
> this case, in my understanding, this patch inserts new entries into the
> list temporarily and immediately moves them to the main GIN data structure
> ginInsertCleanup(). Am I right? If so, that is obviously inefficient.

Sorry, There are incorrect expressions. I mean gin_fast_limit > 0 and
fast_cache_size = 0.

Although I asked this question, I've reconsidered about these parameters, and it
seems that these parameters not only make code rather complex but are a little
confusing to users. So I'd like to propose to introduce only one parameter:
fast_cache_size. While users that give weight to update performance for the
fast update technique set this parameter to a large value, users that give
weight not only to update performance but to search performance set this
parameter to a small value. What do you think about this?


Best regards,
Etsuro Fujita

In response to


Browse pgsql-hackers by date

  From Date Subject
Next Message Rushabh Lathia 2013-09-27 09:34:00 Re: insert throw error when year field len > 4 for timestamptz datatype
Previous Message Andres Freund 2013-09-27 08:42:48 Re: Wait free LW_SHARED acquisition