Re: [HACKERS] Clock with Adaptive Replacement

вс, 29 апр. 2018 г., 2:17 Peter Geoghegan : > On Sat, Apr 28, 2018 at 7:39 AM, Stephen Frost wrote: > > Perhaps I'm misunderstanding the case here, but with the ring buffer we > > use for sequential access, aren't we already discouraging keeping heap > > pages

Re: Explain buffers wrong counter with parallel plans

On Fri, Apr 20, 2018 at 6:36 PM, Adrien Nayrat wrote: > Hello, > > I tried to understand this issue and it seems Gather node only take account of > this own buffer usage : > > > create unlogged table t1 (c1 int); > insert into t1 select generate_series(1,100); >

Re: Explain buffers wrong counter with parallel plans

On Wed, Mar 28, 2018 at 12:07 AM, Adrien Nayrat wrote: > Hello, > > I notice Explain report wrong counters with parallel plans : > > create unlogged table t1 (c1 int); > insert into t1 select generate_series(1,1); > vacuum t1; > > (stop PG, drop caches,start) >

Re: [HACKERS] Clock with Adaptive Replacement

On 2018-04-25 11:31:12 +0500, Andrey Borodin wrote: > > > > 24 апр. 2018 г., в 23:14, Andres Freund написал(а): > > > > On 2018-04-24 17:16:47 +0500, Andrey Borodin wrote: > >> But, I think that cost of development of real page eviction strategy > >> itself is neglectable

Re: power() function in Windows: "value out of range: underflow"

Huong Dangminh writes: >> 2018-04-11 0:13 GMT-03:00 David Rowley : >>> I can recreate this when building with MSVC 2012. I confirm that I see >>> the same as you. Microsoft are setting errno to EDOM in the above 3 >>> cases, where in Linux

Re: Implementing SQL ASSERTION

On Sun, Apr 29, 2018 at 07:18:00PM +0100, Joe Wildish wrote: > On 28 Mar 2018, at 16:13, David Fetter wrote: > > > > Sorry to bother you again, but this now doesn't compile atop master. > > Attached is a rebased patch for the prototype. Thanks! This is great timing for the

Re: Accounting of zero-filled buffers in EXPLAIN (BUFFERS)

On Mon, Apr 30, 2018 at 3:13 PM, Andres Freund wrote: > On 2018-04-30 14:59:31 +1200, Thomas Munro wrote: >> In EXPLAIN (BUFFERS), there are two kinds of cache misses that show up >> as "reads" when in fact they are not reads at all: >> >> 1. Relation extension, which in fact

Re: Postgres, fsync, and OSs (specifically linux)

Hrm, something else that just came up. On 9.6+ we use sync_file_range. It's surely going to eat errors: rc = sync_file_range(fd, offset, nbytes, SYNC_FILE_RANGE_WRITE); /* don't error out, this is just a performance optimization */ if (rc !=

Re: PostgreSQL's handling of fsync() errors is unsafe and risks data loss at least on XFS

For archive readers, this thread is continued as https://www.postgresql.org/message-id/20180427222842.in2e4mibx45zd...@alap3.anarazel.de and there's a follow-up lwn article at https://lwn.net/Articles/752613/ too.

Intermittent ECPG test failures on Windows buildfarm machines

Observe the following buildfarm failures: https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=whelk=2018-03-29%2013%3A41%3A13 https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=woodlouse=2018-04-18%2016%3A42%3A03

Re: power() function in Windows: "value out of range: underflow"

On 30 April 2018 at 07:24, Tom Lane wrote: > Pushed. I'd mainly note that you need to update all the variant float8 > expected-files, not just the primary one. (Sometimes this requires a > bit of guesswork, but here we're expecting all platforms to produce > the same result.

Re: Cold welcoming message when installing anything because of LLVM bitcode stuff

On Sat, Apr 28, 2018 at 02:32:06PM -0400, Tom Lane wrote: > Ugh. I'd tried the core code but not contrib. Will look. The thread has stalled a bit. What are the other issues you were seeing? Are those related to --with-llvm? On my side, if I just apply something like the attached I am able to

Re: Cold welcoming message when installing anything because of LLVM bitcode stuff

On Sun, Apr 29, 2018 at 03:49:53PM -0700, Andres Freund wrote: > Isn't that what bc19b7836215b1a847524041a1bd138d7bb5cbef did? Oops, sorry. Missed this one. -- Michael signature.asc Description: PGP signature

Re: Postgres, fsync, and OSs (specifically linux)

On Sun, Apr 29, 2018 at 1:58 PM, Craig Ringer wrote: > On 28 April 2018 at 23:25, Simon Riggs wrote: >> On 27 April 2018 at 15:28, Andres Freund wrote: >>> While I'm a bit concerned adding user-code before a checkpoint, if >>>

Re: Is a modern build system acceptable for older platforms

> > Which is nice > OK Again, nice > Yeah, that's nice I already use CMake I'd do it, personally > I suppose we have no one silver bullet reason to change autoconf+make to CMake but it's cumulative impression. Also, I suppose this thread started to resolve at least one small question.

Re: Postgres, fsync, and OSs (specifically linux)

> Not quite sure what you're getting at with "a file we don't fsync" - if > we don't, we don't care about durability anyway, no? Or do you mean > where we fsync in a different process? Right. > Either way, the answer is mostly no: On NFS et al where close() implies > an fsync you'll get the

Accounting of zero-filled buffers in EXPLAIN (BUFFERS)

Hi, In EXPLAIN (BUFFERS), there are two kinds of cache misses that show up as "reads" when in fact they are not reads at all: 1. Relation extension, which in fact writes a zero-filled block. 2. The RBM_ZERO_* modes, which provoke neither read nor write. Here's a suggested fix. I noticed this

Re: Local partitioned indexes and pageinspect

On Mon, Apr 23, 2018 at 9:58 PM, Michael Paquier wrote: > Hm, the docs about taking backups with the low-level APIs don't care > much about relkind now: > https://www.postgresql.org/docs/devel/static/continuous-archiving.html#BACKUP-LOWLEVEL-BASE-BACKUP > Or do you have

Re: Postgres, fsync, and OSs (specifically linux)

On 2018-04-30 10:14:23 +0800, Craig Ringer wrote: > Meanwhile, do we know if, on Linux 4.13+, if we get a buffered write > error due to dirty writeback before we close() a file we don't > fsync(), we'll get the error on close()? Not quite sure what you're getting at with "a file we don't fsync" -

Re: power() function in Windows: "value out of range: underflow"

David Rowley writes: > Wouldn't this machine have returned 1 before this patch though? No, don't think so, because it doesn't set EDOM for the case. Basically what we're doing here is making sure that we get results conforming to current POSIX even on machines that

Re: Cold welcoming message when installing anything because of LLVM bitcode stuff

On 2018-04-30 07:43:46 +0900, Michael Paquier wrote: > On Sat, Apr 28, 2018 at 02:32:06PM -0400, Tom Lane wrote: > > Ugh. I'd tried the core code but not contrib. Will look. > > The thread has stalled a bit. Huh? It's a weekend. The last message was yesterday afternoon. > What are the other

Re: Postgres, fsync, and OSs (specifically linux)

On Sun, Apr 29, 2018 at 10:42 PM, Simon Riggs wrote: > On 28 April 2018 at 09:15, Andres Freund wrote: >> On 2018-04-28 08:25:53 -0700, Simon Riggs wrote: >>> The people I've spoken to so far have encouraged us to continue >>> working with the

Re: power() function in Windows: "value out of range: underflow"

On 30 April 2018 at 10:22, Tom Lane wrote: > David Rowley writes: >> Wouldn't this machine have returned 1 before this patch though? > > No, don't think so, because it doesn't set EDOM for the case. > > Basically what we're doing here is making

Re: Is a modern build system acceptable for older platforms

> > this is not about having a working build environment, it is about having > a fully working and correct source tarball before distributing it as a > new release. Sorry, I did not understand correctly it before. I suppose it's not big problem especial if you have CI and tests farm. And anyway

Re: Postgres, fsync, and OSs (specifically linux)

On 30 April 2018 at 09:09, Thomas Munro wrote: > Considering the variety in interpretation and liberties taken, I > wonder if fsync() is underspecified and someone should file an issue > over at http://www.opengroup.org/austin/ about that. All it's going to

Re: power() function in Windows: "value out of range: underflow"

David Rowley writes: > You patch fixes the problem for me, and importantly the two following > cases still work: > postgres=# select power(1,'NaN'); > power > --- > 1 > (1 row) > postgres=# select power('NaN', 0); > power > --- > 1 > (1 row) >

Re: power() function in Windows: "value out of range: underflow"

On 30 April 2018 at 09:19, Tom Lane wrote: > http://netbsd.gw.com/cgi-bin/man-cgi?pow+3+NetBSD-5.2.3 > > which goes to great lengths to justify NaN^0 = 1 while saying nothing > to suggest that 1^NaN might not yield NaN. > > I'm not sure if we should add more special-case code

Re: power() function in Windows: "value out of range: underflow"

David Rowley writes: > I wonder if it's better just to hard code these two cases before even > calling the pow() function. Yeah, see my followup --- I also found out that SUSv2 (POSIX 1997) doesn't require either of these special cases, which helps explain why the

Re: Postgres, fsync, and OSs (specifically linux)

On Mon, Apr 30, 2018 at 11:02 AM, Thomas Munro wrote: > MySQL: The default is still buffered Someone pulled me up on this off-list: the default is buffered (fsync) on Unix, but it's unbuffered on Windows. That's quite interesting.

Re: Accounting of zero-filled buffers in EXPLAIN (BUFFERS)

On 2018-04-30 14:59:31 +1200, Thomas Munro wrote: > Hi, > > In EXPLAIN (BUFFERS), there are two kinds of cache misses that show up > as "reads" when in fact they are not reads at all: > > 1. Relation extension, which in fact writes a zero-filled block. > 2. The RBM_ZERO_* modes, which provoke

Re: Transform for pl/perl

Peter Eisentraut writes: > On 4/24/18 14:31, Andrew Dunstan wrote: >> There is the routine IsValidJsonNumber that helps - see among others >> hstore_io.c for an example use. > I would need something like that taking a double/float8 input. But I > think there is

Re: Postgres, fsync, and OSs (specifically linux)

On 28 April 2018 at 09:15, Andres Freund wrote: > Hi, > > On 2018-04-28 08:25:53 -0700, Simon Riggs wrote: >> > - Use direct IO. Due to architectural performance issues in PG and the >> > fact that it'd not be applicable for all installations I don't think >> > this is a

Re: Postgres, fsync, and OSs (specifically linux)

On 28 April 2018 at 08:25, Simon Riggs wrote: > On 27 April 2018 at 15:28, Andres Freund wrote: > >> - Add a pre-checkpoint hook that checks for filesystem errors *after* >> fsyncing all the files, but *before* logging the checkpoint completion >>

GSoC 2018: thrift encoding format

Hi Aleksander, Start to study the format of thrift encoding format (binary protocol) and found this document( https://erikvanoosten.github.io/thrift-missing-specification/#_struct_encoding). Having one question. Can I assume the data in thrift is always send inside a struct? Otherwise, it

Re: Toast issues with OldestXmin going backwards

On Sun, Apr 29, 2018 at 11:56 AM, Andrew Gierth wrote: >> "Amit" == Amit Kapila writes: > > >>> (Or do we need to track it across restarts? maybe we do, to deal with > >>> replication slaves without slots, or changes in parameters) > >

Re: Verbosity of genbki.pl

On Sat, Apr 28, 2018 at 01:02:10PM -0400, Stephen Frost wrote: > +1 for making them not output anything if all is well. +1. -- Michael signature.asc Description: PGP signature

Re: Toast issues with OldestXmin going backwards

On Fri, Apr 27, 2018 at 8:33 PM, Robert Haas wrote: > On Thu, Apr 26, 2018 at 9:03 PM, Andrew Gierth > wrote: >>(Or do we need to track it across restarts? maybe we do, to deal with >>replication slaves without slots, or changes in