Re: Online enabling of checksums

Hi, I've just noticed the patch does not update src/backend/storage/page/README which is in fact about checksums. Most of it remains valid, but it also mentions that currently it's an initdb-time choice. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL

Re: Online enabling of checksums

On 03/27/2018 08:56 AM, Magnus Hagander wrote: > On Mon, Mar 26, 2018 at 10:09 PM, Tomas Vondra > > wrote: > > Hi, > > I see enable_data_checksums() does this: > >     if (cost_limit <= 0) >        

Re: Online enabling of checksums

On Mon, Mar 26, 2018 at 10:09 PM, Tomas Vondra wrote: > Hi, > > I see enable_data_checksums() does this: > > if (cost_limit <= 0) > ereport(ERROR, > (errmsg("cost limit must be a positive value"))); > > Is there a reason not to allow -1

Re: Online enabling of checksums

Hi, I see enable_data_checksums() does this: if (cost_limit <= 0) ereport(ERROR, (errmsg("cost limit must be a positive value"))); Is there a reason not to allow -1 (no limit), just like for vacuum_cost? regards -- Tomas Vondra

Re: Online enabling of checksums

On Mon, Mar 19, 2018 at 7:27 AM, Heikki Linnakangas wrote: > Hi, > > The patch looks good to me at a high level. Some notes below. I didn't > read through the whole thread, so sorry if some of these have been > discussed already. > > +void >>

Re: Online enabling of checksums

On Tue, Mar 20, 2018 at 10:29 AM, Andrey Borodin wrote: > Hi! > > > 19 марта 2018 г., в 11:27, Heikki Linnakangas > написал(а): > > > > Is there no way to stop the checksum helper once it's started? That > seems rather user-unfriendly. I can imagine it

Re: Online enabling of checksums

Hi! > 19 марта 2018 г., в 11:27, Heikki Linnakangas написал(а): > > Is there no way to stop the checksum helper once it's started? That seems > rather user-unfriendly. I can imagine it being a pretty common mistake to > call pg_enable_data_checksums() on a 10 TB cluster, only

Re: Online enabling of checksums

Hi Magnus! > 19 марта 2018 г., в 16:57, Magnus Hagander написал(а): > > On Mon, Mar 19, 2018 at 12:24 PM, Magnus Hagander > wrote: > On Mon, Mar 19, 2018 at 11:40 AM, Andrey Borodin

Re: Online enabling of checksums

On Mon, Mar 19, 2018 at 12:24 PM, Magnus Hagander wrote: > On Mon, Mar 19, 2018 at 11:40 AM, Andrey Borodin > wrote: > >> Hi, Daniel! >> >> > 19 марта 2018 г., в 4:01, Daniel Gustafsson >> написал(а): >> > >> > Fixed in patch just

Re: Online enabling of checksums

On Mon, Mar 19, 2018 at 11:40 AM, Andrey Borodin wrote: > Hi, Daniel! > > > 19 марта 2018 г., в 4:01, Daniel Gustafsson > написал(а): > > > > Fixed in patch just posted in 84693D0C-772F-45C2-88A1- > 85b4983a5...@yesql.se > > (version 5). Thanks! > > > I've

Re: Online enabling of checksums

Hi, Daniel! > 19 марта 2018 г., в 4:01, Daniel Gustafsson написал(а): > > Fixed in patch just posted in 84693d0c-772f-45c2-88a1-85b4983a5...@yesql.se > (version 5). Thanks! I've been hacking a bit in neighboring thread. And come across one interesting thing. There was a patch

Re: Online enabling of checksums

Hi, The patch looks good to me at a high level. Some notes below. I didn't read through the whole thread, so sorry if some of these have been discussed already. +void +ShutdownChecksumHelperIfRunning(void) +{ + if (pg_atomic_unlocked_test_flag(>launcher_started)) + { +

Re: Online enabling of checksums

> On 18 Mar 2018, at 15:02, Michael Banck wrote: > On Thu, Mar 15, 2018 at 02:01:26PM +0100, Daniel Gustafsson wrote: >>> On 10 Mar 2018, at 16:09, Michael Banck wrote: >>> I am aware that this is discussed already, but as-is the user

Re: Online enabling of checksums

Hi! > 18 марта 2018 г., в 19:02, Michael Banck > написал(а): > > Otherwise, I had a quick look over v4 and found no further issues. > Hopefully I will be able to test it on some bigger test databases next > week. > > I'm switching the state back to 'Waiting on

Re: Online enabling of checksums

Hi, On Thu, Mar 15, 2018 at 02:01:26PM +0100, Daniel Gustafsson wrote: > > On 10 Mar 2018, at 16:09, Michael Banck wrote: > > I am aware that this is discussed already, but as-is the user experience > > is pretty bad, I think pg_enable_data_checksums() should either

Re: Online enabling of checksums

> On 10 Mar 2018, at 16:09, Michael Banck wrote: > I had a closer look at v3 of the patch now. Thanks, much appreciated! Sorry for the late response, just came back from a conference and have had little time for hacking. All whitespace, punctuation and

Re: Online enabling of checksums

Hi, I had a closer look at v3 of the patch now. On Sat, Mar 03, 2018 at 07:23:31PM +0100, Magnus Hagander wrote: > Attached is a rebased patch which removes this optimization, updates the > pg_proc entry for the new format, and changes pg_verify_checksums to use -r > instead of -o for

Re: Online enabling of checksums

Hi, On Mon, Mar 05, 2018 at 11:09:02AM +0100, Magnus Hagander wrote: > On Mon, Mar 5, 2018 at 10:43 AM, Michael Banck > wrote: > > I still find that confusing, but maybe it's just me. I thought the one > > in the pageheader is the "expected" checksum, and we compare

Re: Online enabling of checksums

On Mon, Mar 5, 2018 at 10:43 AM, Michael Banck wrote: > Hi, > > Am Sonntag, den 04.03.2018, 23:30 +0100 schrieb Daniel Gustafsson: > > Agreed. Looking at our current error messages, “in file” is > conventionally > > followed by the filename. I do however think

Re: Online enabling of checksums

Hi, Am Sonntag, den 04.03.2018, 23:30 +0100 schrieb Daniel Gustafsson: > Agreed. Looking at our current error messages, “in file” is conventionally > followed by the filename. I do however think “calculated” is better than > “expected” since it conveys clearly that the compared checksum is

Re: Online enabling of checksums

> On 04 Mar 2018, at 15:24, Michael Banck wrote: >> +csum = pg_checksum_page(buf, blockno + segmentno*RELSEG_SIZE); >> +if (csum != header->pd_checksum) >> +{ >> +if (ControlFile->data_checksum_version == >>

Re: Online enabling of checksums

Hi, On Sat, Mar 03, 2018 at 07:23:31PM +0100, Magnus Hagander wrote: > diff --git a/src/bin/pg_verify_checksums/pg_verify_checksums.c > b/src/bin/pg_verify_checksums/pg_verify_checksums.c > new file mode 100644 > index 00..a4bfe7284d > --- /dev/null > +++

Re: Online enabling of checksums

On Sat, Mar 3, 2018 at 5:17 PM, Tomas Vondra wrote: > > > On 03/03/2018 05:08 PM, Magnus Hagander wrote: > > > > > > On Sat, Mar 3, 2018 at 5:06 PM, Tomas Vondra > > > > wrote: > > > > On

Re: Online enabling of checksums

On 03/03/2018 05:08 PM, Magnus Hagander wrote: > > > On Sat, Mar 3, 2018 at 5:06 PM, Tomas Vondra > > wrote: > > On 03/03/2018 01:38 PM, Robert Haas wrote: > > On Sat, Mar 3, 2018 at 7:32 AM, Robert Haas

Re: Online enabling of checksums

On Sat, Mar 3, 2018 at 5:06 PM, Tomas Vondra wrote: > On 03/03/2018 01:38 PM, Robert Haas wrote: > > On Sat, Mar 3, 2018 at 7:32 AM, Robert Haas > wrote: > >> On Fri, Mar 2, 2018 at 6:26 PM, Tomas Vondra > >>

Re: Online enabling of checksums

On 03/03/2018 01:38 PM, Robert Haas wrote: > On Sat, Mar 3, 2018 at 7:32 AM, Robert Haas wrote: >> On Fri, Mar 2, 2018 at 6:26 PM, Tomas Vondra >> wrote: >>> Hmmm, OK. So we need to have a valid checksum on a page, disable >>> checksums, set

Re: Online enabling of checksums

On Sat, Mar 3, 2018 at 7:32 AM, Robert Haas wrote: > On Fri, Mar 2, 2018 at 6:26 PM, Tomas Vondra > wrote: >> Hmmm, OK. So we need to have a valid checksum on a page, disable >> checksums, set some hint bits on the page (which won't be

Re: Online enabling of checksums

On Fri, Mar 2, 2018 at 6:26 PM, Tomas Vondra wrote: > Hmmm, OK. So we need to have a valid checksum on a page, disable > checksums, set some hint bits on the page (which won't be WAL-logged), > enable checksums again and still get a valid checksum even with the new >

Re: Online enabling of checksums

On 03/02/2018 11:01 PM, Magnus Hagander wrote: > On Fri, Mar 2, 2018 at 5:50 PM, Tomas Vondra > > wrote: > > > > On 03/02/2018 02:35 PM, Magnus Hagander wrote: > > > > > > On Wed, Feb 28, 2018 at 6:06 PM, Robert

Re: Online enabling of checksums

On Fri, Mar 2, 2018 at 5:50 PM, Tomas Vondra wrote: > > > On 03/02/2018 02:35 PM, Magnus Hagander wrote: > > > > > > On Wed, Feb 28, 2018 at 6:06 PM, Robert Haas > > wrote: > > > > On Sun, Feb 25, 2018 at

Re: Online enabling of checksums

On 03/02/2018 02:35 PM, Magnus Hagander wrote: > > > On Wed, Feb 28, 2018 at 6:06 PM, Robert Haas > wrote: > > On Sun, Feb 25, 2018 at 9:54 AM, Magnus Hagander > > wrote: > >

Re: Online enabling of checksums

On Fri, Mar 2, 2018 at 2:44 AM, Andres Freund wrote: > And even more so, I'm not even sure it makes sense to try to get this > into v11. This is a medium-large complicated feature, submitted to the > last CF for v11. That's pretty late. Now, Magnus is a committer, but >

Re: Online enabling of checksums

On Fri, Mar 2, 2018 at 8:35 AM, Magnus Hagander wrote: > Do we ever make hintbit changes on the standby for example? If so, it would > definitely cause problems. I didn't realize we did, actually... We do not. > I guess we could get there even if we don't by: > * All

Re: Online enabling of checksums

On 03/02/2018 03:22 PM, Magnus Hagander wrote: > > > On Fri, Mar 2, 2018 at 3:17 PM, Alvaro Herrera > wrote: > > Magnus Hagander wrote: > > On Wed, Feb 28, 2018 at 10:07 PM, Tomas Vondra >

Re: Online enabling of checksums

On Fri, Mar 2, 2018 at 3:17 PM, Alvaro Herrera wrote: > Magnus Hagander wrote: > > On Wed, Feb 28, 2018 at 10:07 PM, Tomas Vondra < > tomas.von...@2ndquadrant.com > > > > I'd argue this is merely a mistake in the --help text. Firstly, > > > relfilenodes are OIDs too, so

Re: Online enabling of checksums

Magnus Hagander wrote: > On Wed, Feb 28, 2018 at 10:07 PM, Tomas Vondra > I'd argue this is merely a mistake in the --help text. Firstly, > > relfilenodes are OIDs too, so I don't think "-o" is incorrect. Secondly, > > the SGML docs actually say: > Yeah, that one

Re: Online enabling of checksums

On Wed, Feb 28, 2018 at 6:06 PM, Robert Haas wrote: > On Sun, Feb 25, 2018 at 9:54 AM, Magnus Hagander > wrote: > > Also if that wasn't clear -- we only do the full page write if there > isn't > > already a checksum on the page and that checksum is

Re: Online enabling of checksums

On Wed, Feb 28, 2018 at 10:07 PM, Tomas Vondra wrote: > On 02/28/2018 08:42 PM, Alvaro Herrera wrote: > > I noticed that pg_verify_checksum takes an "-o oid" argument to only > > check the relation with that OID; but that's wrong, because the number > > is a

Re: Online enabling of checksums

On Fri, Mar 2, 2018 at 8:44 AM, Andres Freund wrote: > On 2018-03-01 16:18:48 +0100, Magnus Hagander wrote: > > On Thu, Mar 1, 2018 at 9:04 AM, Andres Freund > wrote: > > > > > On 2018-03-01 12:56:35 +0500, Andrey Borodin wrote: > > > > I've tried to

Re: Online enabling of checksums

On 2018-03-01 16:18:48 +0100, Magnus Hagander wrote: > On Thu, Mar 1, 2018 at 9:04 AM, Andres Freund wrote: > > > On 2018-03-01 12:56:35 +0500, Andrey Borodin wrote: > > > I've tried to rebase this patch to 10 and, despite minor rebase issues > > (oids, bgw_type, changes to

Re: Online enabling of checksums

On Thu, Mar 1, 2018 at 9:04 AM, Andres Freund wrote: > On 2018-03-01 12:56:35 +0500, Andrey Borodin wrote: > > I've tried to rebase this patch to 10 and, despite minor rebase issues > (oids, bgw_type, changes to specscanner), patch works fine. > > Do we provide backporting

Re: Online enabling of checksums

On 2018-03-01 12:56:35 +0500, Andrey Borodin wrote: > I've tried to rebase this patch to 10 and, despite minor rebase issues (oids, > bgw_type, changes to specscanner), patch works fine. > Do we provide backporting for such features? Definitely not. With very rare exceptions (OS compatibility

Re: Online enabling of checksums

On Thu, Mar 01, 2018 at 12:56:35PM +0500, Andrey Borodin wrote: > I've tried to rebase this patch to 10 and, despite minor rebase issues > (oids, bgw_type, changes to specscanner), patch works fine. Do we > provide backporting for such features? New features are not backported in upstream.

Re: Online enabling of checksums

> 28 февр. 2018 г., в 6:22, Daniel Gustafsson написал(а): > >> Is there any way we could provide this functionality for previous versions >> (9.6,10)? Like implement utility for offline checksum enabling, without >> WAL-logging, surely. > > While outside the scope of the

Re: Online enabling of checksums

> 28 февр. 2018 г., в 22:06, Robert Haas написал(а): > > On Sun, Feb 25, 2018 at 9:54 AM, Magnus Hagander wrote: >> Also if that wasn't clear -- we only do the full page write if there isn't >> already a checksum on the page and that checksum is

Re: Online enabling of checksums

On 1 March 2018 at 03:42, Alvaro Herrera wrote: > I noticed that pg_verify_checksum takes an "-o oid" argument to only > check the relation with that OID; but that's wrong, because the number > is a relfilenode, not an OID (since it's compared to the on-disk file >

Re: Online enabling of checksums

> On 01 Mar 2018, at 05:07, Tomas Vondra wrote: > > On 02/28/2018 08:42 PM, Alvaro Herrera wrote: >> I noticed that pg_verify_checksum takes an "-o oid" argument to only >> check the relation with that OID; but that's wrong, because the number >> is a relfilenode,

Re: Online enabling of checksums

On 02/28/2018 08:42 PM, Alvaro Herrera wrote: > I noticed that pg_verify_checksum takes an "-o oid" argument to only > check the relation with that OID; but that's wrong, because the number > is a relfilenode, not an OID (since it's compared to the on-disk file > name). I would suggest changing

Re: Online enabling of checksums

I noticed that pg_verify_checksum takes an "-o oid" argument to only check the relation with that OID; but that's wrong, because the number is a relfilenode, not an OID (since it's compared to the on-disk file name). I would suggest changing everything to clarify that it's a pg_class.relfilenode

Re: Online enabling of checksums

On Sun, Feb 25, 2018 at 9:54 AM, Magnus Hagander wrote: > Also if that wasn't clear -- we only do the full page write if there isn't > already a checksum on the page and that checksum is correct. Hmm. Suppose that on the master there is a checksum on the page and that

Re: Online enabling of checksums

> On 28 Feb 2018, at 00:51, Andrey Borodin wrote: > >> 25 февр. 2018 г., в 21:17, Magnus Hagander написал(а): >> >> PFA an updated patch that adds this, and also fixes the problem in >> pg_verify_checksums spotted by Michael Banck. > > I had to

Re: Online enabling of checksums

Hi, Magus! > 25 февр. 2018 г., в 21:17, Magnus Hagander написал(а): > > PFA an updated patch that adds this, and also fixes the problem in > pg_verify_checksums spotted by Michael Banck. I had to ALLOW_CONNECTIONS to template0 to make it work postgres=# 2018-02-27

Re: Online enabling of checksums

> On 26 Feb 2018, at 05:48, Tomas Vondra wrote: > On 02/24/2018 10:45 PM, Magnus Hagander wrote: >> Is it really that invisible? Given how much we argue over adding >> single counters to the stats system, I'm not sure it's quite that >> low. > > I'm a bit unsure

Re: Online enabling of checksums

On 02/24/2018 10:45 PM, Magnus Hagander wrote: > On Sat, Feb 24, 2018 at 1:34 AM, Robert Haas > wrote: > > On Thu, Feb 22, 2018 at 3:28 PM, Magnus Hagander > > wrote: > > I would

Re: Online enabling of checksums

On 02/25/2018 03:57 PM, Magnus Hagander wrote: > > ... > >> > I very strongly doubg it's a "very noticeable operational problem". People >> > > don't restart their databases very often... Let's say it takes 2-3 weeks >> > to >> > > complete a run in a fairly large database. How many such large

Re: Online enabling of checksums

On 02/24/2018 03:51 AM, Stephen Frost wrote: > Greetings, > > * Tomas Vondra (tomas.von...@2ndquadrant.com) wrote: >> On 02/24/2018 03:11 AM, Andres Freund wrote: >>> On 2018-02-24 03:07:28 +0100, Tomas Vondra wrote: I agree having to restart the whole operation after a crash is not

Re: Online enabling of checksums

On Sat, Feb 24, 2018 at 10:48 PM, Magnus Hagander wrote: > On Sat, Feb 24, 2018 at 4:29 AM, Tomas Vondra < > tomas.von...@2ndquadrant.com> wrote: > >> Hi, >> >> I see the patch also does throttling by calling vacuum_delay_point(). >> Being able to throttle the checksum

Re: Online enabling of checksums

On Sat, Feb 24, 2018 at 11:06 PM, Andres Freund wrote: > Hi, > > On 2018-02-24 22:56:57 +0100, Magnus Hagander wrote: > > On Sat, Feb 24, 2018 at 10:49 PM, Andres Freund > wrote: > > > > We did consider doing it at a per-table basis as well. But this is >

Re: Online enabling of checksums

On Sun, Feb 25, 2018 at 1:21 AM, Greg Stark wrote: > > The change of the checksum state is WAL logged with a new xlog record. > All the buffers written by the background worker are forcibly enabled full > page writes to make sure the checksum is fully updated on the standby even >

Re: Online enabling of checksums

> The change of the checksum state is WAL logged with a new xlog record. All > the buffers written by the background worker are forcibly enabled full page > writes to make sure the checksum is fully updated on the standby even if no > actual contents of the buffer changed. Hm. That doesn't

Re: Online enabling of checksums

Hi, On 2018-02-24 22:56:57 +0100, Magnus Hagander wrote: > On Sat, Feb 24, 2018 at 10:49 PM, Andres Freund wrote: > > > We did consider doing it at a per-table basis as well. But this is also > > an > > > overhead that has to be paid forever, whereas the risk of having to

Re: Online enabling of checksums

On Sat, Feb 24, 2018 at 10:49 PM, Andres Freund wrote: > On 2018-02-24 22:45:09 +0100, Magnus Hagander wrote: > > Is it really that invisible? Given how much we argue over adding single > > counters to the stats system, I'm not sure it's quite that low. > > That's appears to

Re: Online enabling of checksums

On Sat, Feb 24, 2018 at 6:14 PM, Michael Banck wrote: > Hi, > > On Wed, Feb 21, 2018 at 09:53:31PM +0100, Magnus Hagander wrote: > > We’ve also included a small commandline tool, bin/pg_verify_checksums, > > that can be run against an offline cluster to validate all

Re: Online enabling of checksums

On 2018-02-24 22:45:09 +0100, Magnus Hagander wrote: > Is it really that invisible? Given how much we argue over adding single > counters to the stats system, I'm not sure it's quite that low. That's appears to be entirely unrelated. The stats stuff is expensive because we currently have to

Re: Online enabling of checksums

On Sat, Feb 24, 2018 at 4:29 AM, Tomas Vondra wrote: > Hi, > > I see the patch also does throttling by calling vacuum_delay_point(). > Being able to throttle the checksum workers not to affect user activity > definitely seems like a useful feature, no complaints

Re: Online enabling of checksums

On Sat, Feb 24, 2018 at 1:34 AM, Robert Haas wrote: > On Thu, Feb 22, 2018 at 3:28 PM, Magnus Hagander > wrote: > > I would prefer that yes. But having to re-read 9TB is still significantly > > better than not being able to turn on checksums at all

Re: Online enabling of checksums

Hi, On Wed, Feb 21, 2018 at 09:53:31PM +0100, Magnus Hagander wrote: > We’ve also included a small commandline tool, bin/pg_verify_checksums, > that can be run against an offline cluster to validate all checksums. The way it is coded in the patch will make pg_verify_checksums fail for heap files

Re: Online enabling of checksums

Hi, I see the patch also does throttling by calling vacuum_delay_point(). Being able to throttle the checksum workers not to affect user activity definitely seems like a useful feature, no complaints here. But perhaps binding it to vacuum_cost_limit/vacuum_cost_delay is not the best idea? I

Re: Online enabling of checksums

Greetings, * Tomas Vondra (tomas.von...@2ndquadrant.com) wrote: > On 02/24/2018 03:11 AM, Andres Freund wrote: > > On 2018-02-24 03:07:28 +0100, Tomas Vondra wrote: > >> I agree having to restart the whole operation after a crash is not > >> ideal, but I don't see how adding a flag actually

Re: Online enabling of checksums

On 02/24/2018 03:11 AM, Andres Freund wrote: > Hi, > > On 2018-02-24 03:07:28 +0100, Tomas Vondra wrote: >> I agree having to restart the whole operation after a crash is not >> ideal, but I don't see how adding a flag actually solves it. The problem >> is the large databases often store most

Re: Online enabling of checksums

Hi, On 2018-02-24 03:07:28 +0100, Tomas Vondra wrote: > I agree having to restart the whole operation after a crash is not > ideal, but I don't see how adding a flag actually solves it. The problem > is the large databases often store most of the data (>80%) in one or two > central tables (think

Re: Online enabling of checksums

On 02/24/2018 01:34 AM, Robert Haas wrote: > On Thu, Feb 22, 2018 at 3:28 PM, Magnus Hagander wrote: >> I would prefer that yes. But having to re-read 9TB is still significantly >> better than not being able to turn on checksums at all (state today). And >> adding a catalog

Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 3:28 PM, Magnus Hagander wrote: > I would prefer that yes. But having to re-read 9TB is still significantly > better than not being able to turn on checksums at all (state today). And > adding a catalog column for it will carry the cost of the

Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 9:09 PM, Peter Eisentraut < peter.eisentr...@2ndquadrant.com> wrote: > On 2/22/18 12:38, Magnus Hagander wrote: > > I'm not entirely sure which the others ones are. Auto-Vacuum obviously > > is one, which doesn't use the worker infrastructure. But I'm not sure > > which

Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 9:48 PM, Michael Paquier wrote: > On Thu, Feb 22, 2018 at 11:24:37AM -0800, Andres Freund wrote: >> I suspect I'm going to get some grief for this, but I think the time has >> come to bite the bullet and support changing databases in the same >>

Re: Online enabling of checksums

How does: On 2018-02-23 11:48:16 +0900, Michael Paquier wrote: > On Thu, Feb 22, 2018 at 11:24:37AM -0800, Andres Freund wrote: > > I suspect I'm going to get some grief for this, but I think the time has > > come to bite the bullet and support changing databases in the same > > process... > >

Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 11:24:37AM -0800, Andres Freund wrote: > I suspect I'm going to get some grief for this, but I think the time has > come to bite the bullet and support changing databases in the same > process... I'd like to see that. Last time this has been discussed, and Robert

Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 9:23 PM, Andres Freund wrote: > Hi, > > On 2018-02-22 21:16:02 +0100, Magnus Hagander wrote: > > You could do that, but then you've moving the complexity to managing that > > list in shared memory instead. > > Maybe I'm missing something, but how are

Re: Online enabling of checksums

Hi, On 2018-02-22 21:16:02 +0100, Magnus Hagander wrote: > You could do that, but then you've moving the complexity to managing that > list in shared memory instead. Maybe I'm missing something, but how are you going to get quick parallel processing if you don't have a shmem piece? You can't

Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 8:52 PM, Andres Freund wrote: > > > On February 22, 2018 11:44:17 AM PST, Magnus Hagander > wrote: > >On Thu, Feb 22, 2018 at 8:41 PM, Andres Freund > >wrote: > >In this particular case that would at least

Re: Online enabling of checksums

On 2/22/18 12:38, Magnus Hagander wrote: > I'm not entirely sure which the others ones are. Auto-Vacuum obviously > is one, which doesn't use the worker infrastructure. But I'm not sure > which the others are referring to?  autovacuum, subscription workers, auto prewarm -- Peter Eisentraut

Re: Online enabling of checksums

On February 22, 2018 11:44:17 AM PST, Magnus Hagander wrote: >On Thu, Feb 22, 2018 at 8:41 PM, Andres Freund >wrote: >In this particular case that would at least phase 1 simplify it because >we'd only need one process instead of worker/launcher.

Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 8:41 PM, Andres Freund wrote: > > On 2018-02-22 20:30:52 +0100, Magnus Hagander wrote: > > On Thu, Feb 22, 2018 at 8:24 PM, Andres Freund > wrote: > > > I suspect I'm going to get some grief for this, but I think the time > has > >

Re: Online enabling of checksums

Hi, On 2018-02-22 20:30:52 +0100, Magnus Hagander wrote: > On Thu, Feb 22, 2018 at 8:24 PM, Andres Freund wrote: > > I suspect I'm going to get some grief for this, but I think the time has > > come to bite the bullet and support changing databases in the same > > process...

Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 8:24 PM, Andres Freund wrote: > On 2018-02-22 08:22:48 -0500, Peter Eisentraut wrote: > > On 2/21/18 15:53, Magnus Hagander wrote: > > > *Two new functions are added, pg_enable_data_checksums() and > > > pg_disable_data_checksums(). The disable one is

Re: Online enabling of checksums

On 2018-02-22 08:22:48 -0500, Peter Eisentraut wrote: > On 2/21/18 15:53, Magnus Hagander wrote: > > *Two new functions are added, pg_enable_data_checksums() and > > pg_disable_data_checksums(). The disable one is easy -- it just changes > > to disable. The enable one will change the state to

Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 4:47 PM, Andrey Borodin wrote: > Hello, Magnus, Peter! > > I'm excited that this feature emerged, thanks for the patch. Hope it will > help to fix some mistakes made during initdb long time ago... > > 22 февр. 2018 г., в 18:22, Peter Eisentraut

Re: Online enabling of checksums

Hello, Magnus, Peter! I'm excited that this feature emerged, thanks for the patch. Hope it will help to fix some mistakes made during initdb long time ago... > 22 февр. 2018 г., в 18:22, Peter Eisentraut > написал(а): > > On 2/21/18 15:53, Magnus Hagander

Re: Online enabling of checksums

On 2/21/18 15:53, Magnus Hagander wrote: > *Two new functions are added, pg_enable_data_checksums() and > pg_disable_data_checksums(). The disable one is easy -- it just changes > to disable. The enable one will change the state to inprogress, and then > start a background worker (the

Re: Online enabling of checksums

Re-sending this one with proper formatting. Apologies for the horrible gmail-screws-up-the-text-part of the last one! No change to patch or text, just the formatting. //Magnus Once more, here is an attempt to solve the problem of on-line enabling of checksums that me and Daniel have been

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