Re: [HACKERS] Problem with background worker
Marc Cousin escribió: > On 20/03/2013 16:33, Alvaro Herrera wrote: > >Ah. The reason for this problem is that the statement start time (which > >also sets the transaction start time, when it's the first statement) is > >set by postgres.c, not the transaction-control functions in xact.c. So > >you'd need to add a SetCurrentStatementStartTimestamp() call somewhere > >in your loop. > > > > Yes, that works. Thanks a lot ! > > Maybe this should be added to the worker_spi example ? Done in http://git.postgresql.org/pg/commitdiff/e543631f3c162ab5f6020b1d0209e0353ca2229a -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Problem with background worker
On Wed, 2013-03-20 at 13:13 -0300, Alvaro Herrera wrote: > Marc Cousin escribió: > > On 20/03/2013 16:33, Alvaro Herrera wrote: > > > >Ah. The reason for this problem is that the statement start time (which > > >also sets the transaction start time, when it's the first statement) is > > >set by postgres.c, not the transaction-control functions in xact.c. So > > >you'd need to add a SetCurrentStatementStartTimestamp() call somewhere > > >in your loop. > > > > Yes, that works. Thanks a lot ! > > > > Maybe this should be added to the worker_spi example ? > > Yeah, I think I need to go over the postgres.c code and figure out what > else needs to be called. I have a pending patch from Guillaume to > improve worker_spi some more; I'll add this bit too. > Happy to know that you still remember it :) Thanks. -- Guillaume http://blog.guillaume.lelarge.info http://www.dalibo.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Problem with background worker
Marc Cousin escribió: > On 20/03/2013 16:33, Alvaro Herrera wrote: > >Ah. The reason for this problem is that the statement start time (which > >also sets the transaction start time, when it's the first statement) is > >set by postgres.c, not the transaction-control functions in xact.c. So > >you'd need to add a SetCurrentStatementStartTimestamp() call somewhere > >in your loop. > > Yes, that works. Thanks a lot ! > > Maybe this should be added to the worker_spi example ? Yeah, I think I need to go over the postgres.c code and figure out what else needs to be called. I have a pending patch from Guillaume to improve worker_spi some more; I'll add this bit too. -- Álvaro Herrerahttp://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
Re: [HACKERS] Problem with background worker
On 20/03/2013 16:33, Alvaro Herrera wrote:
Marc Cousin escribió:
Hi,
I'm trying to write a background writer, and I'm facing a problem with
timestamps. The following code is where I'm having a problem (it's just a demo
for
the problem):
BackgroundWorkerInitializeConnection("test", NULL);
while (!got_sigterm)
{
int ret;
/* Wait 1s */
ret = WaitLatch(&MyProc->procLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
1000L);
ResetLatch(&MyProc->procLatch);
/* Insert dummy for now */
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
ret = SPI_execute("INSERT INTO log VALUES
(now(),statement_timestamp(),clock_timestamp())", false, 0);
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
}
Ah. The reason for this problem is that the statement start time (which
also sets the transaction start time, when it's the first statement) is
set by postgres.c, not the transaction-control functions in xact.c. So
you'd need to add a SetCurrentStatementStartTimestamp() call somewhere
in your loop.
Yes, that works. Thanks a lot !
Maybe this should be added to the worker_spi example ?
Regards
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Re: [HACKERS] Problem with background worker
Marc Cousin escribió:
> Hi,
>
> I'm trying to write a background writer, and I'm facing a problem with
> timestamps. The following code is where I'm having a problem (it's just a
> demo for
> the problem):
>
> BackgroundWorkerInitializeConnection("test", NULL);
> while (!got_sigterm)
> {
> int ret;
> /* Wait 1s */
> ret = WaitLatch(&MyProc->procLatch,
> WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
> 1000L);
> ResetLatch(&MyProc->procLatch);
> /* Insert dummy for now */
> StartTransactionCommand();
> SPI_connect();
> PushActiveSnapshot(GetTransactionSnapshot());
> ret = SPI_execute("INSERT INTO log VALUES
> (now(),statement_timestamp(),clock_timestamp())", false, 0);
> SPI_finish();
> PopActiveSnapshot();
> CommitTransactionCommand();
> }
Ah. The reason for this problem is that the statement start time (which
also sets the transaction start time, when it's the first statement) is
set by postgres.c, not the transaction-control functions in xact.c. So
you'd need to add a SetCurrentStatementStartTimestamp() call somewhere
in your loop.
--
Álvaro Herrerahttp://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
--
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[HACKERS] Problem with background worker
Hi,
I'm trying to write a background writer, and I'm facing a problem with
timestamps. The following code is where I'm having a problem (it's just a demo
for
the problem):
BackgroundWorkerInitializeConnection("test", NULL);
while (!got_sigterm)
{
int ret;
/* Wait 1s */
ret = WaitLatch(&MyProc->procLatch,
WL_LATCH_SET | WL_TIMEOUT | WL_POSTMASTER_DEATH,
1000L);
ResetLatch(&MyProc->procLatch);
/* Insert dummy for now */
StartTransactionCommand();
SPI_connect();
PushActiveSnapshot(GetTransactionSnapshot());
ret = SPI_execute("INSERT INTO log VALUES
(now(),statement_timestamp(),clock_timestamp())", false, 0);
SPI_finish();
PopActiveSnapshot();
CommitTransactionCommand();
}
\d log
Column| Type | Modifiers
-+--+---
now | timestamp with time zone |
statement_timestamp | timestamp with time zone |
clock_timestamp | timestamp with time zone |
Here is its content. Only the clock_timestamp is right. There are missing
records at the
beginning because i truncated the table for this example.
now | statement_timestamp |
clock_timestamp
---+---+---
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:01:52.77683+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:01:53.784301+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:01:54.834212+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:01:55.848497+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:01:56.872671+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:01:57.888461+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:01:58.912448+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:01:59.936335+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:02:00.951247+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:02:01.967937+01
2013-03-20 15:01:44.618623+01 | 2013-03-20 15:01:44.618623+01 | 2013-03-20
15:02:02.983613+01
Most of the code is copy/paste from worker_spi (I don't really understand the
PushActiveSnapshot(GetTransactionSnapshot()) and PopActiveSnapshot() but the
behaviour is the same with or without them, and they were in worker_spi).
I guess I'm doing something wrong, but I really dont't know what it is.
Should I attach the whole code ?
Regards,
Marc
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