From: | Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> |
---|---|
To: | Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> |
Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Michael Paquier <michael(dot)paquier(at)gmail(dot)com>, Jesper Pedersen <jesper(dot)pedersen(at)redhat(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Microvacuum support for Hash Index |
Date: | 2017-03-17 15:04:08 |
Message-ID: | CAE9k0PnkFBpGbz5feX4qA2F4rx5qYmsxfWu5wM85ZM1Rc9TkyA@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Fri, Mar 17, 2017 at 6:13 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> On Fri, Mar 17, 2017 at 12:27 PM, Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote:
>> On Fri, Mar 17, 2017 at 8:20 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>>
>> As I said in my previous e-mail, I think you need
>>> to record clearing of this flag in WAL record XLOG_HASH_DELETE as you
>>> are not doing this unconditionally and then during replay clear it
>>> only when the WAL record indicates the same.
>>
>> Thank you so much for putting that point. I too think that we should
>> record the flag status in the WAL record and clear it only when
>> required during replay.
>>
>
> I think hashdesc.c needs an update (refer case XLOG_HASH_DELETE:).
Done. Thanks!
>
> - * flag. Clearing this flag is just a hint; replay won't redo this.
> + * flag. Clearing this flag is just a hint; replay will check the
> + * status of clear_dead_marking flag before redo it.
> */
> if (tuples_removed && *tuples_removed > 0 &&
> opaque->hasho_flag & LH_PAGE_HAS_DEAD_TUPLES)
> + {
> opaque->hasho_flag &= ~LH_PAGE_HAS_DEAD_TUPLES;
> + clear_dead_marking = true;
> + }
>
>
> I feel the above comment is not required as you are logging this
> action explicitly.
That's right. I have removed it in the attached v4 patch.
>
> + bool clear_dead_marking; /* TRUE if VACUUM clears
>
> No need to write VACUUM explicitly, you can simply say "TRUE if this
> operation clears ...".
Corrected. Please find the attached v4 patch.
--
With Regards,
Ashutosh Sharma
EnterpriseDB:http://www.enterprisedb.com
Attachment | Content-Type | Size |
---|---|---|
0001-Reset-LH_PAGE_HAS_DEAD_TUPLES-flag-during-replay-v4.patch | binary/octet-stream | 5.4 KB |
From | Date | Subject | |
---|---|---|---|
Next Message | Alvaro Herrera | 2017-03-17 15:06:07 | Re: [COMMITTERS] pgsql: Remove objname/objargs split for referring to objects |
Previous Message | Peter Eisentraut | 2017-03-17 14:59:33 | Re: PATCH: pageinspect / add page_checksum and bt_page_items(bytea) |