diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index 583cce7..84334e6 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -106,7 +106,8 @@ ALTER SERVER testserver1 OPTIONS (
sslcert 'value',
sslkey 'value',
sslrootcert 'value',
- sslcrl 'value'
+ sslcrl 'value',
+ fetch_size '101'
--requirepeer 'value',
-- krbsrvname 'value',
-- gsslib 'value',
@@ -114,18 +115,34 @@ ALTER SERVER testserver1 OPTIONS (
);
ALTER USER MAPPING FOR public SERVER testserver1
OPTIONS (DROP user, DROP password);
-ALTER FOREIGN TABLE ft1 OPTIONS (schema_name 'S 1', table_name 'T 1');
+ALTER FOREIGN TABLE ft1 OPTIONS (schema_name 'S 1', table_name 'T 1', fetch_size '102');
ALTER FOREIGN TABLE ft2 OPTIONS (schema_name 'S 1', table_name 'T 1');
ALTER FOREIGN TABLE ft1 ALTER COLUMN c1 OPTIONS (column_name 'C 1');
ALTER FOREIGN TABLE ft2 ALTER COLUMN c1 OPTIONS (column_name 'C 1');
\det+
- List of foreign tables
- Schema | Table | Server | FDW Options | Description
---------+-------+----------+---------------------------------------+-------------
- public | ft1 | loopback | (schema_name 'S 1', table_name 'T 1') |
- public | ft2 | loopback | (schema_name 'S 1', table_name 'T 1') |
+ List of foreign tables
+ Schema | Table | Server | FDW Options | Description
+--------+-------+----------+---------------------------------------------------------+-------------
+ public | ft1 | loopback | (schema_name 'S 1', table_name 'T 1', fetch_size '102') |
+ public | ft2 | loopback | (schema_name 'S 1', table_name 'T 1') |
(2 rows)
+-- Test what options made it into pg_foreign_server.
+-- Filter for just the server we created.
+SELECT srvoptions FROM pg_foreign_server WHERE srvname = 'testserver1';
+ srvoptions
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ {use_remote_estimate=false,updatable=true,fdw_startup_cost=123.456,fdw_tuple_cost=0.123,service=value,connect_timeout=value,dbname=value,host=value,hostaddr=value,port=value,application_name=value,keepalives=value,keepalives_idle=value,keepalives_interval=value,sslcompression=value,sslmode=value,sslcert=value,sslkey=value,sslrootcert=value,sslcrl=value,fetch_size=101}
+(1 row)
+
+-- Test what options made it into pg_foreign_table.
+-- Filter this heavily because we cannot specify which foreign server.
+SELECT ftoptions FROM pg_foreign_table WHERE ftoptions @> array['table_name=T 1','fetch_size=102'];
+ ftoptions
+-----------------------------------------------------
+ {"schema_name=S 1","table_name=T 1",fetch_size=102}
+(1 row)
+
-- Now we should be able to run ANALYZE.
-- To exercise multiple code paths, we use local stats on ft1
-- and remote-estimate mode on ft2.
diff --git a/contrib/postgres_fdw/option.c b/contrib/postgres_fdw/option.c
index 7547ec2..2a3ab7d 100644
--- a/contrib/postgres_fdw/option.c
+++ b/contrib/postgres_fdw/option.c
@@ -153,6 +153,12 @@ InitPgFdwOptions(void)
/* updatable is available on both server and table */
{"updatable", ForeignServerRelationId, false},
{"updatable", ForeignTableRelationId, false},
+ /*
+ * fetch_size is available on both server and table, the table setting
+ * overrides the server setting.
+ */
+ {"fetch_size", ForeignServerRelationId, false},
+ {"fetch_size", ForeignTableRelationId, false},
{NULL, InvalidOid, false}
};
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index 63f0577..733ffb6 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -134,6 +134,7 @@ typedef struct PgFdwScanState
/* extracted fdw_private data */
char *query; /* text of SELECT command */
List *retrieved_attrs; /* list of retrieved attribute numbers */
+ int fetch_size; /* number of tuples per fetch */
/* for remote query execution */
PGconn *conn; /* connection for the scan */
@@ -871,6 +872,22 @@ postgresGetForeignPlan(PlannerInfo *root,
fdw_private);
}
+static DefElem*
+get_option(List *options, char *optname)
+{
+ ListCell *lc;
+
+ foreach(lc, options)
+ {
+ DefElem *def = (DefElem *) lfirst(lc);
+
+ if (strcmp(def->defname, optname) == 0)
+ return def;
+ }
+ return NULL;
+}
+
+
/*
* postgresBeginForeignScan
* Initiate an executor scan of a foreign PostgreSQL table.
@@ -889,6 +906,7 @@ postgresBeginForeignScan(ForeignScanState *node, int eflags)
int numParams;
int i;
ListCell *lc;
+ DefElem *def;
/*
* Do nothing in EXPLAIN (no ANALYZE) case. node->fdw_state stays NULL.
@@ -915,6 +933,23 @@ postgresBeginForeignScan(ForeignScanState *node, int eflags)
server = GetForeignServer(table->serverid);
user = GetUserMapping(userid, server->serverid);
+ /* Reading table options */
+ fsstate->fetch_size = -1;
+
+ def = get_option(table->options, "fetch_size");
+ if (!def)
+ def = get_option(server->options, "fetch_size");
+
+ if (def)
+ {
+ fsstate->fetch_size = strtod(defGetString(def), NULL);
+ if (fsstate->fetch_size < 0)
+ elog(ERROR, "invalid fetch size for foreign table \"%s\"",
+ get_rel_name(table->relid));
+ }
+ else
+ fsstate->fetch_size = 100;
+
/*
* Get connection to the foreign server. Connection manager will
* establish new connection if necessary.
@@ -2031,7 +2066,7 @@ fetch_more_data(ForeignScanState *node)
int i;
/* The fetch size is arbitrary, but shouldn't be enormous. */
- fetch_size = 100;
+ fetch_size = fsstate->fetch_size;
snprintf(sql, sizeof(sql), "FETCH %d FROM c%u",
fetch_size, fsstate->cursor_number);
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 83e8fa7..d12925a 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -115,7 +115,8 @@ ALTER SERVER testserver1 OPTIONS (
sslcert 'value',
sslkey 'value',
sslrootcert 'value',
- sslcrl 'value'
+ sslcrl 'value',
+ fetch_size '101'
--requirepeer 'value',
-- krbsrvname 'value',
-- gsslib 'value',
@@ -123,12 +124,20 @@ ALTER SERVER testserver1 OPTIONS (
);
ALTER USER MAPPING FOR public SERVER testserver1
OPTIONS (DROP user, DROP password);
-ALTER FOREIGN TABLE ft1 OPTIONS (schema_name 'S 1', table_name 'T 1');
+ALTER FOREIGN TABLE ft1 OPTIONS (schema_name 'S 1', table_name 'T 1', fetch_size '102');
ALTER FOREIGN TABLE ft2 OPTIONS (schema_name 'S 1', table_name 'T 1');
ALTER FOREIGN TABLE ft1 ALTER COLUMN c1 OPTIONS (column_name 'C 1');
ALTER FOREIGN TABLE ft2 ALTER COLUMN c1 OPTIONS (column_name 'C 1');
\det+
+-- Test what options made it into pg_foreign_server.
+-- Filter for just the server we created.
+SELECT srvoptions FROM pg_foreign_server WHERE srvname = 'testserver1';
+
+-- Test what options made it into pg_foreign_table.
+-- Filter this heavily because we cannot specify which foreign server.
+SELECT ftoptions FROM pg_foreign_table WHERE ftoptions @> array['table_name=T 1','fetch_size=102'];
+
-- Now we should be able to run ANALYZE.
-- To exercise multiple code paths, we use local stats on ft1
-- and remote-estimate mode on ft2.
diff --git a/doc/src/sgml/postgres-fdw.sgml b/doc/src/sgml/postgres-fdw.sgml
index 43adb61..02b004d 100644
--- a/doc/src/sgml/postgres-fdw.sgml
+++ b/doc/src/sgml/postgres-fdw.sgml
@@ -294,6 +294,34 @@
+ Fetch Size Options
+
+
+ By default, rows are fetched from the remote server 100 at a time.
+ This may be overridden using the following option:
+
+
+
+
+
+ fetch_size
+
+
+ This option specifies the number of rows postgres_fdw
+ should get in each fetch operation. It can be specified for a foreign
+ table or a foreign server. The option specified on a table overrides
+ an option specified for the server.
+ The default is 100.
+
+
+
+
+
+
+
+
+
+
Importing Options