From 449ab6350526e99d33363706b759951ebad7928e Mon Sep 17 00:00:00 2001 From: Fujii Masao Date: Tue, 7 Sep 2021 12:27:30 +0900 Subject: postgres_fdw: Allow application_name of remote connection to be set via GUC. This commit adds postgres_fdw.application_name GUC which specifies a value for application_name configuration parameter used when postgres_fdw establishes a connection to a foreign server. This GUC setting always overrides application_name option of the foreign server object. This GUC is useful when we want to specify our own application_name per remote connection. Previously application_name of a remote connection could be set basically only via options of a server object. But which meant that every session connecting to the same foreign server basically should use the same application_name. Also if we want to change the setting, we had to execute "ALTER SERVER ... OPTIONS ..." command. It was inconvenient. Author: Hayato Kuroda Reviewed-by: Masahiro Ikeda, Fujii Masao Discussion: https://postgr.es/m/TYCPR01MB5870D1E8B949DAF6D3B84E02F5F29@TYCPR01MB5870.jpnprd01.prod.outlook.com --- contrib/postgres_fdw/option.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) (limited to 'contrib/postgres_fdw/option.c') diff --git a/contrib/postgres_fdw/option.c b/contrib/postgres_fdw/option.c index c574ca2cf39..5bb1af4084a 100644 --- a/contrib/postgres_fdw/option.c +++ b/contrib/postgres_fdw/option.c @@ -1,7 +1,7 @@ /*------------------------------------------------------------------------- * * option.c - * FDW option handling for postgres_fdw + * FDW and GUC option handling for postgres_fdw * * Portions Copyright (c) 2012-2021, PostgreSQL Global Development Group * @@ -45,6 +45,13 @@ static PgFdwOption *postgres_fdw_options; */ static PQconninfoOption *libpq_options; +/* + * GUC parameters + */ +char *pgfdw_application_name = NULL; + +void _PG_init(void); + /* * Helper functions */ @@ -435,3 +442,29 @@ ExtractExtensionList(const char *extensionsString, bool warnOnMissing) list_free(extlist); return extensionOids; } + +/* + * Module load callback + */ +void +_PG_init(void) +{ + /* + * Unlike application_name GUC, don't set GUC_IS_NAME flag nor check_hook + * to allow postgres_fdw.application_name to be any string more than + * NAMEDATALEN characters and to include non-ASCII characters. Instead, + * remote server truncates application_name of remote connection to less + * than NAMEDATALEN and replaces any non-ASCII characters in it with a '?' + * character. + */ + DefineCustomStringVariable("postgres_fdw.application_name", + "Sets the application name to be used on the remote server.", + NULL, + &pgfdw_application_name, + NULL, + PGC_USERSET, + 0, + NULL, + NULL, + NULL); +} -- cgit v1.2.3