11 files changed, 186 insertions, 1 deletions
diff --git a/src/include/commands/explain.h b/src/include/commands/explain.h
index f17548338f8..2c38c92ae51 100644
--- a/src/include/commands/explain.h
+++ b/src/include/commands/explain.h
@@ -72,4 +72,15 @@ extern void ExplainBeginOutput(ExplainState *es);
 extern void ExplainEndOutput(ExplainState *es);
 extern void ExplainSeparatePlans(ExplainState *es);
 
+extern void ExplainPropertyList(const char *qlabel, List *data,
+								ExplainState *es);
+extern void ExplainPropertyText(const char *qlabel, const char *value,
+								ExplainState *es);
+extern void ExplainPropertyInteger(const char *qlabel, int value,
+								   ExplainState *es);
+extern void ExplainPropertyLong(const char *qlabel, long value,
+								ExplainState *es);
+extern void ExplainPropertyFloat(const char *qlabel, double value, int ndigits,
+								 ExplainState *es);
+
 #endif   /* EXPLAIN_H */
diff --git a/src/include/executor/nodeForeignscan.h b/src/include/executor/nodeForeignscan.h
new file mode 100644
index 00000000000..5cfcfe72d03
--- /dev/null
+++ b/src/include/executor/nodeForeignscan.h
@@ -0,0 +1,24 @@
+/*-------------------------------------------------------------------------
+ *
+ * nodeForeignscan.h
+ *
+ *
+ *
+ * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/executor/nodeForeignscan.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef NODEFOREIGNSCAN_H
+#define NODEFOREIGNSCAN_H
+
+#include "nodes/execnodes.h"
+
+extern ForeignScanState *ExecInitForeignScan(ForeignScan *node, EState *estate, int eflags);
+extern TupleTableSlot *ExecForeignScan(ForeignScanState *node);
+extern void ExecEndForeignScan(ForeignScanState *node);
+extern void ExecReScanForeignScan(ForeignScanState *node);
+
+#endif   /* NODEFOREIGNSCAN_H */
diff --git a/src/include/fmgr.h b/src/include/fmgr.h
index 9720117a7f5..7539acace82 100644
--- a/src/include/fmgr.h
+++ b/src/include/fmgr.h
@@ -488,6 +488,7 @@ extern Datum FunctionCall9(FmgrInfo *flinfo, Datum arg1, Datum arg2,
  * by FunctionCallN().	If the same function is to be invoked repeatedly,
  * do the FunctionLookup() once and then use FunctionCallN().
  */
+extern Datum OidFunctionCall0(Oid functionId);
 extern Datum OidFunctionCall1(Oid functionId, Datum arg1);
 extern Datum OidFunctionCall2(Oid functionId, Datum arg1, Datum arg2);
 extern Datum OidFunctionCall3(Oid functionId, Datum arg1, Datum arg2,
diff --git a/src/include/foreign/fdwapi.h b/src/include/foreign/fdwapi.h
new file mode 100644
index 00000000000..28731873885
--- /dev/null
+++ b/src/include/foreign/fdwapi.h
@@ -0,0 +1,98 @@
+/*-------------------------------------------------------------------------
+ *
+ * fdwapi.h
+ *	  API for foreign-data wrappers
+ *
+ * Copyright (c) 2010-2011, PostgreSQL Global Development Group
+ *
+ * src/include/foreign/fdwapi.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef FDWAPI_H
+#define FDWAPI_H
+
+#include "nodes/execnodes.h"
+#include "nodes/relation.h"
+
+/* To avoid including explain.h here, reference ExplainState thus: */
+struct ExplainState;
+
+
+/*
+ * FdwPlan is the information returned to the planner by PlanForeignScan.
+ */
+typedef struct FdwPlan
+{
+	NodeTag		type;
+
+	/*
+	 * Cost estimation info. The startup_cost is time before retrieving
+	 * the first row, so it should include costs of connecting to the remote
+	 * host, sending over the query, etc.  Note that PlanForeignScan also
+	 * ought to set baserel->rows and baserel->width if it can produce any
+	 * usable estimates of those values.
+	 */
+	Cost		startup_cost;	/* cost expended before fetching any tuples */
+	Cost		total_cost;		/* total cost (assuming all tuples fetched) */
+
+	/*
+	 * FDW private data, which will be available at execution time.
+	 *
+	 * Note that everything in this list must be copiable by copyObject().
+	 * One way to store an arbitrary blob of bytes is to represent it as a
+	 * bytea Const.  Usually, though, you'll be better off choosing a
+	 * representation that can be dumped usefully by nodeToString().
+	 */
+	List	   *fdw_private;
+} FdwPlan;
+
+
+/*
+ * Callback function signatures --- see fdwhandler.sgml for more info.
+ */
+
+typedef FdwPlan * (*PlanForeignScan_function) (Oid foreigntableid,
+											   PlannerInfo *root,
+											   RelOptInfo *baserel);
+
+typedef void (*ExplainForeignScan_function) (ForeignScanState *node,
+											 struct ExplainState *es);
+
+typedef void (*BeginForeignScan_function) (ForeignScanState *node,
+										   int eflags);
+
+typedef TupleTableSlot * (*IterateForeignScan_function) (ForeignScanState *node);
+
+typedef void (*ReScanForeignScan_function) (ForeignScanState *node);
+
+typedef void (*EndForeignScan_function) (ForeignScanState *node);
+
+
+/*
+ * FdwRoutine is the struct returned by a foreign-data wrapper's handler
+ * function.  It provides pointers to the callback functions needed by the
+ * planner and executor.
+ *
+ * Currently, all functions must be supplied.  Later there may be optional
+ * additions.  It's recommended that the handler initialize the struct with
+ * makeNode(FdwRoutine) so that all fields are set to zero.
+ */
+typedef struct FdwRoutine
+{
+	NodeTag		type;
+
+	PlanForeignScan_function PlanForeignScan;
+	ExplainForeignScan_function ExplainForeignScan;
+	BeginForeignScan_function BeginForeignScan;
+	IterateForeignScan_function IterateForeignScan;
+	ReScanForeignScan_function ReScanForeignScan;
+	EndForeignScan_function EndForeignScan;
+} FdwRoutine;
+
+
+/* Functions in foreign/foreign.c */
+extern FdwRoutine *GetFdwRoutine(Oid fdwhandler);
+extern FdwRoutine *GetFdwRoutineByRelId(Oid relid);
+
+#endif   /* FDWAPI_H */
diff --git a/src/include/foreign/foreign.h b/src/include/foreign/foreign.h
index 2cf0eaa09cc..d676f3fce74 100644
--- a/src/include/foreign/foreign.h
+++ b/src/include/foreign/foreign.h
@@ -60,6 +60,13 @@ typedef struct UserMapping
 	List	   *options;		/* useoptions as DefElem list */
 } UserMapping;
 
+typedef struct ForeignTable
+{
+	Oid			relid;			/* relation Oid */
+	Oid			serverid;		/* server Oid */
+	List	   *options;		/* ftoptions as DefElem list */
+} ForeignTable;
+
 
 extern ForeignServer *GetForeignServer(Oid serverid);
 extern ForeignServer *GetForeignServerByName(const char *name, bool missing_ok);
@@ -69,5 +76,6 @@ extern ForeignDataWrapper *GetForeignDataWrapper(Oid fdwid);
 extern ForeignDataWrapper *GetForeignDataWrapperByName(const char *name,
 							bool missing_ok);
 extern Oid	GetForeignDataWrapperOidByName(const char *name, bool missing_ok);
+extern ForeignTable *GetForeignTable(Oid relid);
 
 #endif   /* FOREIGN_H */
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 44da70ff608..0a6b829de4f 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1403,6 +1403,20 @@ typedef struct WorkTableScanState
 	RecursiveUnionState *rustate;
 } WorkTableScanState;
 
+/* ----------------
+ *	 ForeignScanState information
+ *
+ *		ForeignScan nodes are used to scan foreign-data tables.
+ * ----------------
+ */
+typedef struct ForeignScanState
+{
+	ScanState	ss;				/* its first field is NodeTag */
+	/* use struct pointer to avoid including fdwapi.h here */
+	struct FdwRoutine *fdwroutine;
+	void	   *fdw_state;		/* foreign-data wrapper can keep state here */
+} ForeignScanState;
+
 /* ----------------------------------------------------------------
  *				 Join State Information
  * ----------------------------------------------------------------
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index e0d05748daf..cbaf123ee9d 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -60,6 +60,8 @@ typedef enum NodeTag
 	T_ValuesScan,
 	T_CteScan,
 	T_WorkTableScan,
+	T_ForeignScan,
+	T_FdwPlan,
 	T_Join,
 	T_NestLoop,
 	T_MergeJoin,
@@ -103,6 +105,7 @@ typedef enum NodeTag
 	T_ValuesScanState,
 	T_CteScanState,
 	T_WorkTableScanState,
+	T_ForeignScanState,
 	T_JoinState,
 	T_NestLoopState,
 	T_MergeJoinState,
@@ -217,6 +220,7 @@ typedef enum NodeTag
 	T_MergePath,
 	T_HashPath,
 	T_TidPath,
+	T_ForeignPath,
 	T_AppendPath,
 	T_MergeAppendPath,
 	T_ResultPath,
@@ -409,7 +413,8 @@ typedef enum NodeTag
 	T_ReturnSetInfo,			/* in nodes/execnodes.h */
 	T_WindowObjectData,			/* private in nodeWindowAgg.c */
 	T_TIDBitmap,				/* in nodes/tidbitmap.h */
-	T_InlineCodeBlock			/* in nodes/parsenodes.h */
+	T_InlineCodeBlock,			/* in nodes/parsenodes.h */
+	T_FdwRoutine				/* in foreign/fdwapi.h */
 } NodeTag;
 
 /*
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index b4fb4f211b5..90d61256e9c 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -436,6 +436,18 @@ typedef struct WorkTableScan
 	int			wtParam;		/* ID of Param representing work table */
 } WorkTableScan;
 
+/* ----------------
+ *		ForeignScan node
+ * ----------------
+ */
+typedef struct ForeignScan
+{
+	Scan		scan;
+	bool		fsSystemCol;	/* true if any "system column" is needed */
+	/* use struct pointer to avoid including fdwapi.h here */
+	struct FdwPlan *fdwplan;
+} ForeignScan;
+
 
 /*
  * ==========
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index 6f51b6c5fe4..ab708351ed7 100644
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -750,6 +750,16 @@ typedef struct TidPath
 } TidPath;
 
 /*
+ * ForeignPath represents a scan of a foreign table
+ */
+typedef struct ForeignPath
+{
+	Path		path;
+	/* use struct pointer to avoid including fdwapi.h here */
+	struct FdwPlan *fdwplan;
+} ForeignPath;
+
+/*
  * AppendPath represents an Append plan, ie, successive execution of
  * several member plans.
  *
diff --git a/src/include/optimizer/cost.h b/src/include/optimizer/cost.h
index 3112bf75ccf..e3cf7464df6 100644
--- a/src/include/optimizer/cost.h
+++ b/src/include/optimizer/cost.h
@@ -127,6 +127,7 @@ extern void set_function_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 extern void set_values_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 extern void set_cte_size_estimates(PlannerInfo *root, RelOptInfo *rel,
 					   Plan *cteplan);
+extern void set_foreign_size_estimates(PlannerInfo *root, RelOptInfo *rel);
 
 /*
  * prototypes for clausesel.c
diff --git a/src/include/optimizer/pathnode.h b/src/include/optimizer/pathnode.h
index ff220e32a79..7a24da2c51c 100644
--- a/src/include/optimizer/pathnode.h
+++ b/src/include/optimizer/pathnode.h
@@ -61,6 +61,7 @@ extern Path *create_functionscan_path(PlannerInfo *root, RelOptInfo *rel);
 extern Path *create_valuesscan_path(PlannerInfo *root, RelOptInfo *rel);
 extern Path *create_ctescan_path(PlannerInfo *root, RelOptInfo *rel);
 extern Path *create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel);
+extern ForeignPath *create_foreignscan_path(PlannerInfo *root, RelOptInfo *rel);
 
 extern NestPath *create_nestloop_path(PlannerInfo *root,
 					 RelOptInfo *joinrel,