Re: Statement timeout behavior in extended queries

Hello,

I've reviewed the patch. My understanding is as follows. Please correct me if I'm wrong.

* The difference is that the Execute message stops the statement_timeout timer, so that the execution of one statement doesn't shorten the timeout period of subsequent statements when they are run in batch followed by a single Sync message.

* This patch is also necessary (or desirable) for the feature "Pipelining/batch mode support for libpq," which is being developed for PG 10. This patch enables correct timeout handling for each statement execution in a batch. Without this patch, the entire batch of statements is subject to statement_timeout. That's different from what the manual describes about statement_timeout. statement_timeout should measure execution of each statement.

Below are what I found in the patch.

(1)
+static bool st_timeout = false;

I think the variable name would better be stmt_timeout_enabled or stmt_timer_started, because other existing names use stmt to abbreviate statement, and thhis variable represents a state (see xact_started for example.)

(2)
+static void enable_statement_timeout(void)
+{

+static void disable_statement_timeout(void)
+{

"static void" and the remaining line should be on different lines, as other functions do.

(3)
+ /*
+ * Sanity check
+ */
+ if (!xact_started)
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("Transaction must have been already started to set statement timeout")));
+ }

I think this fragment can be deleted, because enable/disable_timeout() is used only at limited places in postgres.c, so I don't see the chance of misuse.

Regards
Takayuki Tsunakawa