Merge branch 'master' of git://git.postgresql.org/git/postgresql

Author: kelvich

config/Makefile

@@ -7,9 +7,11 @@ include $(top_builddir)/src/Makefile.global
 
 install: all installdirs
 	$(INSTALL_SCRIPT) $(srcdir)/install-sh '$(DESTDIR)$(pgxsdir)/config/install-sh'
+	$(INSTALL_SCRIPT) $(srcdir)/missing '$(DESTDIR)$(pgxsdir)/config/missing'
 
 installdirs:
 	$(MKDIR_P) '$(DESTDIR)$(pgxsdir)/config'
 
 uninstall:
 	rm -f '$(DESTDIR)$(pgxsdir)/config/install-sh'
+	rm -f '$(DESTDIR)$(pgxsdir)/config/missing'

contrib/file_fdw/file_fdw.c

@@ -121,7 +121,8 @@ static ForeignScan *fileGetForeignPlan(PlannerInfo *root,
 				   Oid foreigntableid,
 				   ForeignPath *best_path,
 				   List *tlist,
-				   List *scan_clauses);
+				   List *scan_clauses,
+				   Plan *outer_plan);
 static void fileExplainForeignScan(ForeignScanState *node, ExplainState *es);
 static void fileBeginForeignScan(ForeignScanState *node, int eflags);
 static TupleTableSlot *fileIterateForeignScan(ForeignScanState *node);
@@ -525,6 +526,7 @@ fileGetForeignPaths(PlannerInfo *root,
 									 total_cost,
 									 NIL,		/* no pathkeys */
 									 NULL,		/* no outer rel either */
+									 NULL,		/* no extra plan */
 									 coptions));
 
 	/*
@@ -544,7 +546,8 @@ fileGetForeignPlan(PlannerInfo *root,
 				   Oid foreigntableid,
 				   ForeignPath *best_path,
 				   List *tlist,
-				   List *scan_clauses)
+				   List *scan_clauses,
+				   Plan *outer_plan)
 {
 	Index		scan_relid = baserel->relid;
 
@@ -564,7 +567,8 @@ fileGetForeignPlan(PlannerInfo *root,
 							NIL,	/* no expressions to evaluate */
 							best_path->fdw_private,
 							NIL,	/* no custom tlist */
-							NIL /* no remote quals */ );
+							NIL,	/* no remote quals */
+							outer_plan);
 }
 
 /*

contrib/postgres_fdw/postgres_fdw.c

@@ -215,7 +215,8 @@ static ForeignScan *postgresGetForeignPlan(PlannerInfo *root,
 					   Oid foreigntableid,
 					   ForeignPath *best_path,
 					   List *tlist,
-					   List *scan_clauses);
+					   List *scan_clauses,
+					   Plan *outer_plan);
 static void postgresBeginForeignScan(ForeignScanState *node, int eflags);
 static TupleTableSlot *postgresIterateForeignScan(ForeignScanState *node);
 static void postgresReScanForeignScan(ForeignScanState *node);
@@ -536,6 +537,7 @@ postgresGetForeignPaths(PlannerInfo *root,
 								   fpinfo->total_cost,
 								   NIL, /* no pathkeys */
 								   NULL,		/* no outer rel either */
+								   NULL,		/* no extra plan */
 								   NIL);		/* no fdw_private list */
 	add_path(baserel, (Path *) path);
 
@@ -590,6 +592,7 @@ postgresGetForeignPaths(PlannerInfo *root,
 										 total_cost,
 										 usable_pathkeys,
 										 NULL,
+										 NULL,
 										 NIL));
 	}
 
@@ -757,6 +760,7 @@ postgresGetForeignPaths(PlannerInfo *root,
 									   total_cost,
 									   NIL,		/* no pathkeys */
 									   param_info->ppi_req_outer,
+									   NULL,
 									   NIL);	/* no fdw_private list */
 		add_path(baserel, (Path *) path);
 	}
@@ -772,7 +776,8 @@ postgresGetForeignPlan(PlannerInfo *root,
 					   Oid foreigntableid,
 					   ForeignPath *best_path,
 					   List *tlist,
-					   List *scan_clauses)
+					   List *scan_clauses,
+					   Plan *outer_plan)
 {
 	PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) baserel->fdw_private;
 	Index		scan_relid = baserel->relid;
@@ -916,7 +921,8 @@ postgresGetForeignPlan(PlannerInfo *root,
 							params_list,
 							fdw_private,
 							NIL,	/* no custom tlist */
-							remote_exprs);
+							remote_exprs,
+							outer_plan);
 }
 
 /*

doc/src/sgml/earthdistance.sgml

@@ -19,7 +19,7 @@
  <para>
   In this module, the Earth is assumed to be perfectly spherical.
   (If that's too inaccurate for you, you might want to look at the
-  <application><ulink url="http://www.postgis.org/">PostGIS</ulink></>
+  <application><ulink url="http://postgis.net/">PostGIS</ulink></>
   project.)
  </para>
 

doc/src/sgml/external-projects.sgml

@@ -231,7 +231,7 @@
    contains several extensions, which are described in
    <xref linkend="contrib">.  Other extensions are developed
    independently, like <application><ulink
-   url="http://www.postgis.org/">PostGIS</ulink></>.  Even
+   url="http://postgis.net/">PostGIS</ulink></>.  Even
    <productname>PostgreSQL</> replication solutions can be developed
    externally. For example, <application> <ulink
    url="http://www.slony.info">Slony-I</ulink></> is a popular

doc/src/sgml/fdwhandler.sgml

@@ -168,7 +168,8 @@ GetForeignPlan (PlannerInfo *root,
                 Oid foreigntableid,
                 ForeignPath *best_path,
                 List *tlist,
-                List *scan_clauses);
+                List *scan_clauses,
+                Plan *outer_plan);
 </programlisting>
 
      Create a <structname>ForeignScan</> plan node from the selected foreign
@@ -765,6 +766,35 @@ RefetchForeignRow (EState *estate,
      See <xref linkend="fdw-row-locking"> for more information.
     </para>
 
+    <para>
+<programlisting>
+bool
+RecheckForeignScan (ForeignScanState *node, TupleTableSlot *slot);
+</programlisting>
+     Recheck that a previously-returned tuple still matches the relevant
+     scan and join qualifiers, and possibly provide a modified version of
+     the tuple.  For foreign data wrappers which do not perform join pushdown,
+     it will typically be more convenient to set this to <literal>NULL</> and
+     instead set <structfield>fdw_recheck_quals</structfield> appropriately.
+     When outer joins are pushed down, however, it isn't sufficient to
+     reapply the checks relevant to all the base tables to the result tuple,
+     even if all needed attributes are present, because failure to match some
+     qualifier might result in some attributes going to NULL, rather than in
+     no tuple being returned.  <literal>RecheckForeignScan</> can recheck
+     qualifiers and return true if they are still satisfied and false
+     otherwise, but it can also store a replacement tuple into the supplied
+     slot.
+    </para>
+
+    <para>
+     To implement join pushdown, a foreign data wrapper will typically
+     construct an alternative local join plan which is used only for
+     rechecks; this will become the outer subplan of the
+     <literal>ForeignScan</>.  When a recheck is required, this subplan
+     can be executed and the resulting tuple can be stored in the slot.
+     This plan need not be efficient since no base table will return more
+     than one row; for example, it may implement all joins as nested loops.
+    </para>
    </sect2>
 
    <sect2 id="fdw-callbacks-explain">
@@ -1137,11 +1167,17 @@ GetForeignServerByName(const char *name, bool missing_ok);
 
     <para>
      Any clauses removed from the plan node's qual list must instead be added
-     to <literal>fdw_recheck_quals</> in order to ensure correct behavior
+     to <literal>fdw_recheck_quals</> or rechecked by
+     <literal>RecheckForeignScan</> in order to ensure correct behavior
      at the <literal>READ COMMITTED</> isolation level.  When a concurrent
      update occurs for some other table involved in the query, the executor
      may need to verify that all of the original quals are still satisfied for
-     the tuple, possibly against a different set of parameter values.
+     the tuple, possibly against a different set of parameter values.  Using
+     <literal>fdw_recheck_quals</> is typically easier than implementing checks
+     inside <literal>RecheckForeignScan</>, but this method will be
+     insufficient when outer joins have been pushed down, since the join tuples
+     in that case might have some fields go to NULL without rejecting the
+     tuple entirely.
     </para>
 
     <para>