Ashutosh Bapat писал 2022-02-17 16:30:
On Wed, Feb 16, 2022 at 8:38 PM Alexander Pyhalov
<a.pyha...@postgrespro.ru> wrote:
Ashutosh Bapat писал 2022-02-16 16:40:
> On Mon, Feb 14, 2022 at 4:23 PM Alexander Pyhalov
> <a.pyha...@postgrespro.ru> wrote:
>>
> I see that these options will work for all kinds of relations. So no
> problem if foreign table is pointing to something other than a table.
Hi.
The issue is that we perform deparsing while planing, we haven't
connected to server yet.
Are there any ideas how to find out its version without specifying it,
for example, in server options?
Yes, you are right. I wish foreign servers, esp. postgresql, could be
more integrated and if we could defer deparsing till execution phase.
But that's out of scope for this patch.
Hi.
I've updated patch to provide server-level "deparse_wait_policy" option,
which controls if we deparse SKIP LOCKED or SELECT FOR UPDATE (true by
default).
This will make possible for people with old servers to revert to old
behavior.
--
Best regards,
Alexander Pyhalov,
Postgres Professional
From 5f5a0434227debd8ca7ee406e8cb1997edff14a3 Mon Sep 17 00:00:00 2001
From: Alexander Pyhalov <a.pyha...@postgrespro.ru>
Date: Mon, 14 Feb 2022 12:01:26 +0300
Subject: [PATCH] postgres_fdw could pass lock wait policy to foreign server
---
contrib/postgres_fdw/deparse.c | 12 +-
.../postgres_fdw/expected/postgres_fdw.out | 110 +++++++++++++++++-
contrib/postgres_fdw/option.c | 4 +-
contrib/postgres_fdw/postgres_fdw.c | 4 +
contrib/postgres_fdw/postgres_fdw.h | 1 +
contrib/postgres_fdw/sql/postgres_fdw.sql | 18 +++
doc/src/sgml/postgres-fdw.sgml | 16 +++
7 files changed, 161 insertions(+), 4 deletions(-)
diff --git a/contrib/postgres_fdw/deparse.c b/contrib/postgres_fdw/deparse.c
index bf12eac0288..f55afd461f0 100644
--- a/contrib/postgres_fdw/deparse.c
+++ b/contrib/postgres_fdw/deparse.c
@@ -1429,8 +1429,7 @@ deparseLockingClause(deparse_expr_cxt *context)
* For now, just ignore any [NO] KEY specification, since (a)
* it's not clear what that means for a remote table that we
* don't have complete information about, and (b) it wouldn't
- * work anyway on older remote servers. Likewise, we don't
- * worry about NOWAIT.
+ * work anyway on older remote servers.
*/
switch (rc->strength)
{
@@ -1451,6 +1450,15 @@ deparseLockingClause(deparse_expr_cxt *context)
if (bms_membership(rel->relids) == BMS_MULTIPLE &&
rc->strength != LCS_NONE)
appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
+
+ /* Lock behavior */
+ if (fpinfo->deparse_wait_policy && rc->strength != LCS_NONE)
+ {
+ if (rc->waitPolicy == LockWaitSkip)
+ appendStringInfoString(buf, " SKIP LOCKED");
+ else if (rc->waitPolicy == LockWaitError)
+ appendStringInfoString(buf, " NOWAIT");
+ }
}
}
}
diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index b2e02caefe4..b33d61b8656 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -389,6 +389,35 @@ SELECT * FROM ft1 t1 WHERE c1 = 102 FOR SHARE;
102 | 2 | 00102 | Sat Jan 03 00:00:00 1970 PST | Sat Jan 03 00:00:00 1970 | 2 | 2 | foo
(1 row)
+-- test wait policy specification
+EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 WHERE c1 = 101 FOR UPDATE NOWAIT;
+ QUERY PLAN
+-----------------------------------------------------------------------------------------------------------------
+ Foreign Scan on public.ft1 t1
+ Output: c1, c2, c3, c4, c5, c6, c7, c8, t1.*
+ Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" = 101)) FOR UPDATE NOWAIT
+(3 rows)
+
+SELECT * FROM ft1 t1 WHERE c1 = 101 FOR UPDATE NOWAIT;
+ c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
+-----+----+-------+------------------------------+--------------------------+----+------------+-----
+ 101 | 1 | 00101 | Fri Jan 02 00:00:00 1970 PST | Fri Jan 02 00:00:00 1970 | 1 | 1 | foo
+(1 row)
+
+EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 WHERE c1 = 102 FOR SHARE SKIP LOCKED;
+ QUERY PLAN
+---------------------------------------------------------------------------------------------------------------------
+ Foreign Scan on public.ft1 t1
+ Output: c1, c2, c3, c4, c5, c6, c7, c8, t1.*
+ Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" = 102)) FOR SHARE SKIP LOCKED
+(3 rows)
+
+SELECT * FROM ft1 t1 WHERE c1 = 102 FOR SHARE SKIP LOCKED;
+ c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
+-----+----+-------+------------------------------+--------------------------+----+------------+-----
+ 102 | 2 | 00102 | Sat Jan 03 00:00:00 1970 PST | Sat Jan 03 00:00:00 1970 | 2 | 2 | foo
+(1 row)
+
-- aggregate
SELECT COUNT(*) FROM ft1 t1;
count
@@ -1862,6 +1891,59 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
110 | 110
(10 rows)
+-- test wait policy specification
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE SKIP LOCKED;
+ QUERY PLAN
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan
+ Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
+ Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
+ Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint FOR UPDATE OF r1 SKIP LOCKED FOR UPDATE OF r2 SKIP LOCKED
+(4 rows)
+
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE SKIP LOCKED;
+ c1 | c1
+-----+-----
+ 101 | 101
+ 102 | 102
+ 103 | 103
+ 104 | 104
+ 105 | 105
+ 106 | 106
+ 107 | 107
+ 108 | 108
+ 109 | 109
+ 110 | 110
+(10 rows)
+
+ALTER SERVER loopback OPTIONS (ADD deparse_wait_policy 'false');
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE SKIP LOCKED;
+ QUERY PLAN
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan
+ Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
+ Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
+ Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint FOR UPDATE OF r1 FOR UPDATE OF r2
+(4 rows)
+
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE SKIP LOCKED;
+ c1 | c1
+-----+-----
+ 101 | 101
+ 102 | 102
+ 103 | 103
+ 104 | 104
+ 105 | 105
+ 106 | 106
+ 107 | 107
+ 108 | 108
+ 109 | 109
+ 110 | 110
+(10 rows)
+
+ALTER SERVER loopback OPTIONS (DROP deparse_wait_policy);
-- join two tables with FOR SHARE clause
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR SHARE OF t1;
@@ -1913,6 +1995,32 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
110 | 110
(10 rows)
+-- test wait policy specification
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE NOWAIT;
+ QUERY PLAN
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Foreign Scan
+ Output: t1.c1, t2.c1, t1.c3, t1.*, t2.*
+ Relations: (public.ft1 t1) INNER JOIN (public.ft2 t2)
+ Remote SQL: SELECT r1."C 1", r2."C 1", r1.c3, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END FROM ("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) ORDER BY r1.c3 ASC NULLS LAST, r1."C 1" ASC NULLS LAST LIMIT 10::bigint OFFSET 100::bigint FOR UPDATE OF r1 NOWAIT FOR UPDATE OF r2 NOWAIT
+(4 rows)
+
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE NOWAIT;
+ c1 | c1
+-----+-----
+ 101 | 101
+ 102 | 102
+ 103 | 103
+ 104 | 104
+ 105 | 105
+ 106 | 106
+ 107 | 107
+ 108 | 108
+ 109 | 109
+ 110 | 110
+(10 rows)
+
-- join in CTE
EXPLAIN (VERBOSE, COSTS OFF)
WITH t (c1_1, c1_3, c2_1) AS MATERIALIZED (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10;
@@ -9509,7 +9617,7 @@ DO $d$
END;
$d$;
ERROR: invalid option "password"
-HINT: Valid options in this context are: service, passfile, channel_binding, connect_timeout, dbname, host, hostaddr, port, options, application_name, keepalives, keepalives_idle, keepalives_interval, keepalives_count, tcp_user_timeout, sslmode, sslcompression, sslcert, sslkey, sslrootcert, sslcrl, sslcrldir, sslsni, requirepeer, ssl_min_protocol_version, ssl_max_protocol_version, gssencmode, krbsrvname, gsslib, target_session_attrs, use_remote_estimate, fdw_startup_cost, fdw_tuple_cost, extensions, updatable, truncatable, fetch_size, batch_size, async_capable, keep_connections
+HINT: Valid options in this context are: service, passfile, channel_binding, connect_timeout, dbname, host, hostaddr, port, options, application_name, keepalives, keepalives_idle, keepalives_interval, keepalives_count, tcp_user_timeout, sslmode, sslcompression, sslcert, sslkey, sslrootcert, sslcrl, sslcrldir, sslsni, requirepeer, ssl_min_protocol_version, ssl_max_protocol_version, gssencmode, krbsrvname, gsslib, target_session_attrs, use_remote_estimate, fdw_startup_cost, fdw_tuple_cost, extensions, updatable, truncatable, fetch_size, batch_size, async_capable, deparse_wait_policy, keep_connections
CONTEXT: SQL statement "ALTER SERVER loopback_nopw OPTIONS (ADD password 'dummypw')"
PL/pgSQL function inline_code_block line 3 at EXECUTE
-- If we add a password for our user mapping instead, we should get a different
diff --git a/contrib/postgres_fdw/option.c b/contrib/postgres_fdw/option.c
index fc3ce6a53a2..ec92c007862 100644
--- a/contrib/postgres_fdw/option.c
+++ b/contrib/postgres_fdw/option.c
@@ -121,7 +121,8 @@ postgres_fdw_validator(PG_FUNCTION_ARGS)
strcmp(def->defname, "updatable") == 0 ||
strcmp(def->defname, "truncatable") == 0 ||
strcmp(def->defname, "async_capable") == 0 ||
- strcmp(def->defname, "keep_connections") == 0)
+ strcmp(def->defname, "keep_connections") == 0 ||
+ strcmp(def->defname, "deparse_wait_policy") == 0)
{
/* these accept only boolean values */
(void) defGetBoolean(def);
@@ -249,6 +250,7 @@ InitPgFdwOptions(void)
/* async_capable is available on both server and table */
{"async_capable", ForeignServerRelationId, false},
{"async_capable", ForeignTableRelationId, false},
+ {"deparse_wait_policy", ForeignServerRelationId, false},
{"keep_connections", ForeignServerRelationId, false},
{"password_required", UserMappingRelationId, false},
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index 56654844e8f..ead4824e8f3 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -650,6 +650,7 @@ postgresGetForeignRelSize(PlannerInfo *root,
fpinfo->shippable_extensions = NIL;
fpinfo->fetch_size = 100;
fpinfo->async_capable = false;
+ fpinfo->deparse_wait_policy = true;
apply_server_options(fpinfo);
apply_table_options(fpinfo);
@@ -5858,6 +5859,8 @@ apply_server_options(PgFdwRelationInfo *fpinfo)
(void) parse_int(defGetString(def), &fpinfo->fetch_size, 0, NULL);
else if (strcmp(def->defname, "async_capable") == 0)
fpinfo->async_capable = defGetBoolean(def);
+ else if (strcmp(def->defname, "deparse_wait_policy") == 0)
+ fpinfo->deparse_wait_policy = defGetBoolean(def);
}
}
@@ -5916,6 +5919,7 @@ merge_fdw_options(PgFdwRelationInfo *fpinfo,
fpinfo->use_remote_estimate = fpinfo_o->use_remote_estimate;
fpinfo->fetch_size = fpinfo_o->fetch_size;
fpinfo->async_capable = fpinfo_o->async_capable;
+ fpinfo->deparse_wait_policy = fpinfo_o->deparse_wait_policy;
/* Merge the table level options from either side of the join. */
if (fpinfo_i)
diff --git a/contrib/postgres_fdw/postgres_fdw.h b/contrib/postgres_fdw/postgres_fdw.h
index 8ae79e97e44..e4882e70fa4 100644
--- a/contrib/postgres_fdw/postgres_fdw.h
+++ b/contrib/postgres_fdw/postgres_fdw.h
@@ -80,6 +80,7 @@ typedef struct PgFdwRelationInfo
Cost fdw_tuple_cost;
List *shippable_extensions; /* OIDs of shippable extensions */
bool async_capable;
+ bool deparse_wait_policy;
/* Cached catalog information. */
ForeignTable *table;
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index e050639b572..fdd55d76b6d 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -274,6 +274,11 @@ EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 WHERE c1 = 101 FOR UPDATE;
SELECT * FROM ft1 t1 WHERE c1 = 101 FOR UPDATE;
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 WHERE c1 = 102 FOR SHARE;
SELECT * FROM ft1 t1 WHERE c1 = 102 FOR SHARE;
+-- test wait policy specification
+EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 WHERE c1 = 101 FOR UPDATE NOWAIT;
+SELECT * FROM ft1 t1 WHERE c1 = 101 FOR UPDATE NOWAIT;
+EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM ft1 t1 WHERE c1 = 102 FOR SHARE SKIP LOCKED;
+SELECT * FROM ft1 t1 WHERE c1 = 102 FOR SHARE SKIP LOCKED;
-- aggregate
SELECT COUNT(*) FROM ft1 t1;
-- subquery
@@ -566,6 +571,15 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE;
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE;
+-- test wait policy specification
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE SKIP LOCKED;
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE SKIP LOCKED;
+ALTER SERVER loopback OPTIONS (ADD deparse_wait_policy 'false');
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE SKIP LOCKED;
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE SKIP LOCKED;
+ALTER SERVER loopback OPTIONS (DROP deparse_wait_policy);
-- join two tables with FOR SHARE clause
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR SHARE OF t1;
@@ -573,6 +587,10 @@ SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t
EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR SHARE;
SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR SHARE;
+-- test wait policy specification
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE NOWAIT;
+SELECT t1.c1, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c3, t1.c1 OFFSET 100 LIMIT 10 FOR UPDATE NOWAIT;
-- join in CTE
EXPLAIN (VERBOSE, COSTS OFF)
WITH t (c1_1, c1_3, c2_1) AS MATERIALIZED (SELECT t1.c1, t1.c3, t2.c1 FROM ft1 t1 JOIN ft2 t2 ON (t1.c1 = t2.c1)) SELECT c1_1, c2_1 FROM t ORDER BY c1_3, c1_1 OFFSET 100 LIMIT 10;
diff --git a/doc/src/sgml/postgres-fdw.sgml b/doc/src/sgml/postgres-fdw.sgml
index 2bb31f11255..8eb194d1417 100644
--- a/doc/src/sgml/postgres-fdw.sgml
+++ b/doc/src/sgml/postgres-fdw.sgml
@@ -341,6 +341,22 @@ OPTIONS (ADD password_required 'false');
</para>
<variablelist>
+ <varlistentry>
+ <term><literal>deparse_wait_policy</literal> (<type>bool</type>)</term>
+ <listitem>
+ <para>
+ This option determines if <literal>SKIP LOCKED</literal> or
+ <literal>NOWAIT</literal> policy specified in
+ <command>SELECT FOR UPDATE</command> or <command>SELECT FOR SHARE</command>
+ queries should be passed to the remote server.
+ This option can only be specified for foreign servers, not per-table.
+ </para>
+ <para>
+ By default it's true. Note that such statements are not supported
+ by old <productname>PostgreSQL</productname> versions.
+ </para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><literal>extensions</literal> (<type>string</type>)</term>
--
2.25.1
