From 96198d94cb7adc664bda341842dc8db671d8be72 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Thu, 28 Jan 2016 12:05:19 -0500 Subject: Avoid multiple foreign server connections when all use same user mapping. Previously, postgres_fdw's connection cache was keyed by user OID and server OID, but this can lead to multiple connections when it's not really necessary. In particular, if all relevant users are mapped to the public user mapping, then their connection options are certainly the same, so one connection can be used for all of them. While we're cleaning things up here, drop the "server" argument to GetConnection(), which isn't really needed. This saves a few cycles because callers no longer have to look this up; the function itself does, but only when establishing a new connection, not when reusing an existing one. Ashutosh Bapat, with a few small changes by me. --- contrib/postgres_fdw/postgres_fdw.c | 28 ++++++++++------------------ 1 file changed, 10 insertions(+), 18 deletions(-) (limited to 'contrib/postgres_fdw/postgres_fdw.c') diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index 374faf5a25a..a237e152c02 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -1101,7 +1101,6 @@ postgresBeginForeignScan(ForeignScanState *node, int eflags) RangeTblEntry *rte; Oid userid; ForeignTable *table; - ForeignServer *server; UserMapping *user; int numParams; int i; @@ -1129,14 +1128,13 @@ postgresBeginForeignScan(ForeignScanState *node, int eflags) /* Get info about foreign table. */ fsstate->rel = node->ss.ss_currentRelation; table = GetForeignTable(RelationGetRelid(fsstate->rel)); - server = GetForeignServer(table->serverid); - user = GetUserMapping(userid, server->serverid); + user = GetUserMapping(userid, table->serverid); /* * Get connection to the foreign server. Connection manager will * establish new connection if necessary. */ - fsstate->conn = GetConnection(server, user, false); + fsstate->conn = GetConnection(user, false); /* Assign a unique ID for my cursor */ fsstate->cursor_number = GetCursorNumber(fsstate->conn); @@ -1503,7 +1501,6 @@ postgresBeginForeignModify(ModifyTableState *mtstate, RangeTblEntry *rte; Oid userid; ForeignTable *table; - ForeignServer *server; UserMapping *user; AttrNumber n_params; Oid typefnoid; @@ -1530,11 +1527,10 @@ postgresBeginForeignModify(ModifyTableState *mtstate, /* Get info about foreign table. */ table = GetForeignTable(RelationGetRelid(rel)); - server = GetForeignServer(table->serverid); - user = GetUserMapping(userid, server->serverid); + user = GetUserMapping(userid, table->serverid); /* Open connection; report that we'll create a prepared statement. */ - fmstate->conn = GetConnection(server, user, true); + fmstate->conn = GetConnection(user, true); fmstate->p_name = NULL; /* prepared statement not made yet */ /* Deconstruct fdw_private data. */ @@ -1988,7 +1984,7 @@ estimate_path_cost_size(PlannerInfo *root, appendOrderByClause(&sql, root, baserel, pathkeys); /* Get the remote estimate */ - conn = GetConnection(fpinfo->server, fpinfo->user, false); + conn = GetConnection(fpinfo->user, false); get_remote_estimate(sql.data, conn, &rows, &width, &startup_cost, &total_cost); ReleaseConnection(conn); @@ -2544,7 +2540,6 @@ postgresAnalyzeForeignTable(Relation relation, BlockNumber *totalpages) { ForeignTable *table; - ForeignServer *server; UserMapping *user; PGconn *conn; StringInfoData sql; @@ -2565,9 +2560,8 @@ postgresAnalyzeForeignTable(Relation relation, * owner, even if the ANALYZE was started by some other user. */ table = GetForeignTable(RelationGetRelid(relation)); - server = GetForeignServer(table->serverid); - user = GetUserMapping(relation->rd_rel->relowner, server->serverid); - conn = GetConnection(server, user, false); + user = GetUserMapping(relation->rd_rel->relowner, table->serverid); + conn = GetConnection(user, false); /* * Construct command to get page count for relation. @@ -2626,7 +2620,6 @@ postgresAcquireSampleRowsFunc(Relation relation, int elevel, { PgFdwAnalyzeState astate; ForeignTable *table; - ForeignServer *server; UserMapping *user; PGconn *conn; unsigned int cursor_number; @@ -2657,9 +2650,8 @@ postgresAcquireSampleRowsFunc(Relation relation, int elevel, * owner, even if the ANALYZE was started by some other user. */ table = GetForeignTable(RelationGetRelid(relation)); - server = GetForeignServer(table->serverid); - user = GetUserMapping(relation->rd_rel->relowner, server->serverid); - conn = GetConnection(server, user, false); + user = GetUserMapping(relation->rd_rel->relowner, table->serverid); + conn = GetConnection(user, false); /* * Construct cursor that retrieves whole rows from remote. @@ -2860,7 +2852,7 @@ postgresImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid) */ server = GetForeignServer(serverOid); mapping = GetUserMapping(GetUserId(), server->serverid); - conn = GetConnection(server, mapping, false); + conn = GetConnection(mapping, false); /* Don't attempt to import collation if remote server hasn't got it */ if (PQserverVersion(conn) < 90100) -- cgit v1.2.3