Re: Disallowing multiple queries per PQexec()

Surafel Temesgen wrote:

> I modified the patch as such and added to commitfest 2017-07.

A couple comments:

+ {"disallow_multiple_queries", PGC_POSTMASTER,
CLIENT_CONN_OTHER,
+ gettext_noop("Disallow multiple queries per query
string."),
+ NULL
+ },

PGC_POSTMASTER implies that it's an instance-wide setting.
Is is intentional? I can understand that it's more secure for this not to
be changeable in an existing session, but it's also much less usable if you
can't set it per-database and per-user.
Maybe it should be PGC_SUSET ?

+ if ((strcmp(commandTagHead, "BEGIN") != 0) ||
(strcmp(commandTagTail, "COMMIT") != 0) )
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot execute multiple commands unless it is a transaction
block")));

Shouldn't ROLLBACK be considered too as ending a transaction block?
Also, can it use a more specific code than ERRCODE_SYNTAX_ERROR?
It feels more like a rule violation than a syntax error.

Best regards,
--
Daniel Vérité
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