(2014/09/10 12:31), Fujii Masao wrote:
On Wed, Sep 10, 2014 at 12:15 PM, Etsuro Fujita
<fujita.ets...@lab.ntt.co.jp> wrote:
(2014/09/09 22:17), Fujii Masao wrote:
Attached is the updated version of the patch.
I took a quick review on the patch. It looks good to me,
but one thing I'm
concerned about is
You wrote:
The attached patch introduces the GIN index storage parameter
"PENDING_LIST_CLEANUP_SIZE" which specifies the maximum size of
GIN pending list. If it's not set, work_mem is used as that maximum
size,
instead. So this patch doesn't break the existing application which
currently uses work_mem as the threshold of cleanup operation of
the pending list. It has only not to set PENDING_LIST_CLEANUP_SIZE.
As you mentioned, I think it's important to consider for the existing
applications, but I'm wondering if it would be a bit confusing users to have
two parameters,
Yep.
PENDING_LIST_CLEANUP_SIZE and work_mem, for this setting.
Wouldn't it be easy-to-use to have only one parameter,
PENDING_LIST_CLEANUP_SIZE? How about setting PENDING_LIST_CLEANUP_SIZE to
work_mem as the default value when running the CREATE INDEX command?
That's an idea. But there might be some users who want to change
the cleanup size per session like they can do by setting work_mem,
and your idea would prevent them from doing that...
Why not use ALTER INDEX ... SET (PENDING_LIST_CLEANUP_SIZE= ...)? Maybe
I'm missing something, though.
So what about introduing pending_list_cleanup_size also as GUC?
That is, users can set the threshold by using either the reloption or
GUC.
Yeah, that's an idea. So, I'd like to hear the opinions of others.
Thanks,
Best regards,
Etsuro Fujita
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