From 17e9ecac011832959b703b1d6a14788f9c8c829c Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 9 Nov 2022 11:08:52 -0500 Subject: [PATCH] Doc: add comments about PreventInTransactionBlock/IsInTransactionBlock. Add a little to the header comments for these functions to make it clearer what guarantees about commit behavior are provided to callers. (See commit f92944137 for context.) Although this is only a comment change, it's really documentation aimed at authors of extensions, so it seems appropriate to back-patch. Yugo Nagata and Tom Lane, per further discussion of bug #17434. Discussion: https://postgr.es/m/17434-d9f7a064ce2a88a3@postgresql.org --- src/backend/access/transam/xact.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index fa32231e39..d578f11c4d 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -3338,6 +3338,10 @@ AbortCurrentTransaction(void) * a transaction block, typically because they have non-rollback-able * side effects or do internal commits. * + * If this routine completes successfully, then the calling statement is + * guaranteed that if it completes without error, its results will be + * committed immediately. + * * If we have already started a transaction block, issue an error; also issue * an error if we appear to be running inside a user-defined function (which * could issue more commands and possibly cause a failure after the statement @@ -3464,6 +3468,10 @@ CheckTransactionBlock(bool isTopLevel, bool throwError, const char *stmtType) * a transaction block than when running as single commands. ANALYZE is * currently the only example. * + * If this routine returns "false", then the calling statement is + * guaranteed that if it completes without error, its results will be + * committed immediately. + * * isTopLevel: passed down from ProcessUtility to determine whether we are * inside a function. */