Tom Lane 0eff10a008 Send NOTIFY signals during CommitTransaction. ... Formerly, we sent signals for outgoing NOTIFY messages within ProcessCompletedNotifies, which was also responsible for sending relevant ones of those messages to our connected client. It therefore had to run during the main-loop processing that occurs just before going idle. This arrangement had two big disadvantages: * Now that procedures allow intra-command COMMITs, it would be useful to send NOTIFYs to other sessions immediately at COMMIT (though, for reasons of wire-protocol stability, we still shouldn't forward them to our client until end of command). * Background processes such as replication workers would not send NOTIFYs at all, since they never execute the client communication loop. We've had requests to allow triggers running in replication workers to send NOTIFYs, so that's a problem. To fix these things, move transmission of outgoing NOTIFY signals into AtCommit_Notify, where it will happen during CommitTransaction. Also move the possible call of asyncQueueAdvanceTail there, to ensure we don't bloat the async SLRU if a background worker sends many NOTIFYs with no one listening. We can also drop the call of asyncQueueReadAllNotifications, allowing ProcessCompletedNotifies to go away entirely. That's because commit 790026972 added a call of ProcessNotifyInterrupt adjacent to PostgresMain's call of ProcessCompletedNotifies, and that does its own call of asyncQueueReadAllNotifications, meaning that we were uselessly doing two such calls (inside two separate transactions) whenever inbound notify signals coincided with an outbound notify. We need only set notifyInterruptPending to ensure that ProcessNotifyInterrupt runs, and we're done. The existing documentation suggests that custom background workers should call ProcessCompletedNotifies if they want to send NOTIFY messages. To avoid an ABI break in the back branches, reduce it to an empty routine rather than removing it entirely. Removal will occur in v15. Although the problems mentioned above have existed for awhile, I don't feel comfortable back-patching this any further than v13. There was quite a bit of churn in adjacent code between 12 and 13. At minimum we'd have to also backpatch 51004c717, and a good deal of other adjustment would also be needed, so the benefit-to-risk ratio doesn't look attractive. Per bug #15293 from Michael Powers (and similar gripes from others). Artur Zakirov and Tom Lane Discussion: https://postgr.es/m/153243441449.1404.2274116228506175596@wrigleys.postgresql.org		2021-09-14 17:18:25 -04:00
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brin	Fix an asssortment of typos in brin_minmax_multi.c and mcv.c	2021-06-10 20:13:44 +12:00
common	Revert analyze support for partitioned tables	2021-08-16 17:27:52 -04:00
gin	Remove redundant memset(0) calls for page init of some index AMs	2021-04-07 14:35:26 +09:00
gist	Remove redundant variable pageSize in gistinitpage	2021-06-25 07:55:34 +02:00
hash	Further portability tweaks for float4/float8 hash functions.	2021-09-04 16:29:08 -04:00
heap	VACUUM VERBOSE: Don't report "pages removed".	2021-08-31 20:37:17 -07:00
index	Initial pgindent and pgperltidy run for v14.	2021-05-12 13:14:10 -04:00
nbtree	Remove dead assignment to local variable.	2021-07-12 11:13:59 +03:00
rmgrdesc	Improve WAL record descriptions for SP-GiST records.	2021-04-20 17:01:49 -04:00
spgist	Count SP-GiST index scans in pg_stat statistics.	2021-08-27 19:53:06 -04:00
table	Allow configurable LZ4 TOAST compression.	2021-03-19 15:10:38 -04:00
tablesample	Update copyright for 2021	2021-01-02 13:06:25 -05:00
transam	Send NOTIFY signals during CommitTransaction.	2021-09-14 17:18:25 -04:00
Makefile	Introduce access/{table.h, relation.h}, for generic functions from heapam.h.	2019-01-21 10:51:36 -08:00