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Revert "For inplace update, send nontransactional invalidations."

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This reverts commit 95c5acb3fc (v17) and
counterparts in each other non-master branch.  If released, that commit
would have caused a worst-in-years minor release regression, via
undetected LWLock self-deadlock.  This commit and its self-deadlock fix
warrant more bake time in the master branch.

Reported by Alexander Lakhin.

Discussion: https://postgr.es/m/10ec0bc3-5933-1189-6bb8-5dec4114558e@gmail.com
This commit is contained in:
Noah Misch
2024-11-02 09:05:00 -07:00
parent be74b943c9
commit fe8091c9e3
11 changed files with 117 additions and 289 deletions
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26
src/backend/access/transam/xact.c
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@ -1249,24 +1249,14 @@ RecordTransactionCommit(void)
/*
* Transactions without an assigned xid can contain invalidation
* messages. While inplace updates do this, this is not known to be
* necessary; see comment at inplace CacheInvalidateHeapTuple().
* Extensions might still rely on this capability, and standbys may
* need to process those invals. We can't emit a commit record
* without an xid, and we don't want to force assigning an xid,
* because that'd be problematic for e.g. vacuum. Hence we emit a
* bespoke record for the invalidations. We don't want to use that in
* case a commit record is emitted, so they happen synchronously with
* commits (besides not wanting to emit more WAL records).
*
* XXX Every known use of this capability is a defect. Since an XID
* isn't controlling visibility of the change that prompted invals,
* other sessions need the inval even if this transactions aborts.
*
* ON COMMIT DELETE ROWS does a nontransactional index_build(), which
* queues a relcache inval, including in transactions without an xid
* that had read the (empty) table. Standbys don't need any ON COMMIT
* DELETE ROWS invals, but we've not done the work to withhold them.
* messages (e.g. explicit relcache invalidations or catcache
* invalidations for inplace updates); standbys need to process those.
* We can't emit a commit record without an xid, and we don't want to
* force assigning an xid, because that'd be problematic for e.g.
* vacuum. Hence we emit a bespoke record for the invalidations. We
* don't want to use that in case a commit record is emitted, so they
* happen synchronously with commits (besides not wanting to emit more
* WAL records).
*/
if (nmsgs != 0)
{