WITH CHECK OPTION support for auto-updatable VIEWs

For simple views which are automatically updatable, this patch allows
the user to specify what level of checking should be done on records
being inserted or updated.  For 'LOCAL CHECK', new tuples are validated
against the conditionals of the view they are being inserted into, while
for 'CASCADED CHECK' the new tuples are validated against the
conditionals for all views involved (from the top down).

This option is part of the SQL specification.

Dean Rasheed, reviewed by Pavel Stehule

4 files changed, 29 insertions, 0 deletions

diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 5de5db7582..298af26e96 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -303,6 +303,8 @@ typedef struct JunkFilter
  *		TrigInstrument			optional runtime measurements for triggers
  *		FdwRoutine				FDW callback functions, if foreign table
  *		FdwState				available to save private state of FDW
+ *		WithCheckOptions		list of WithCheckOption's for views
+ *		WithCheckOptionExprs	list of WithCheckOption expr states
  *		ConstraintExprs			array of constraint-checking expr states
  *		junkFilter				for removing junk attributes from tuples
  *		projectReturning		for computing a RETURNING list
@@ -322,6 +324,8 @@ typedef struct ResultRelInfo
 	Instrumentation *ri_TrigInstrument;
 	struct FdwRoutine *ri_FdwRoutine;
 	void	   *ri_FdwState;
+	List	   *ri_WithCheckOptions;
+	List	   *ri_WithCheckOptionExprs;
 	List	  **ri_ConstraintExprs;
 	JunkFilter *ri_junkFilter;
 	ProjectionInfo *ri_projectReturning;
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 0d5c007f93..78368c63c1 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -388,6 +388,7 @@ typedef enum NodeTag
 	T_Constraint,
 	T_DefElem,
 	T_RangeTblEntry,
+	T_WithCheckOption,
 	T_SortGroupClause,
 	T_WindowClause,
 	T_PrivGrantee,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 0cefb71505..9415e2c636 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -128,6 +128,8 @@ typedef struct Query
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
+	List	   *withCheckOptions; /* a list of WithCheckOption's */
+
 	List	   *returningList;	/* return-values list (of TargetEntry) */
 
 	List	   *groupClause;	/* a list of SortGroupClause's */
@@ -784,6 +786,19 @@ typedef struct RangeTblEntry
 } RangeTblEntry;
 
 /*
+ * WithCheckOption -
+ *		representation of WITH CHECK OPTION checks to be applied to new tuples
+ *		when inserting/updating an auto-updatable view.
+ */
+typedef struct WithCheckOption
+{
+	NodeTag		type;
+	char	   *viewname;	/* name of view that specified the WCO */
+	Node	   *qual;		/* constraint qual to check */
+	bool		cascaded;	/* true = WITH CASCADED CHECK OPTION */
+} WithCheckOption;
+
+/*
  * SortGroupClause -
  *		representation of ORDER BY, GROUP BY, PARTITION BY,
  *		DISTINCT, DISTINCT ON items
@@ -2333,6 +2348,13 @@ typedef struct AlterEnumStmt
  *		Create View Statement
  * ----------------------
  */
+typedef enum ViewCheckOption
+{
+	NO_CHECK_OPTION,
+	LOCAL_CHECK_OPTION,
+	CASCADED_CHECK_OPTION
+} ViewCheckOption;
+
 typedef struct ViewStmt
 {
 	NodeTag		type;
@@ -2341,6 +2363,7 @@ typedef struct ViewStmt
 	Node	   *query;			/* the SELECT query */
 	bool		replace;		/* replace an existing view? */
 	List	   *options;		/* options from WITH clause */
+	ViewCheckOption	withCheckOption; /* WITH CHECK OPTION */
 } ViewStmt;
 
 /* ----------------------
diff --git a/src/include/nodes/plannodes.h b/src/include/nodes/plannodes.h
index 841701ed98..aa4f12cec5 100644
--- a/src/include/nodes/plannodes.h
+++ b/src/include/nodes/plannodes.h
@@ -172,6 +172,7 @@ typedef struct ModifyTable
 	List	   *resultRelations;	/* integer list of RT indexes */
 	int			resultRelIndex; /* index of first resultRel in plan's list */
 	List	   *plans;			/* plan(s) producing source data */
+	List	   *withCheckOptionLists; /* per-target-table WCO lists */
 	List	   *returningLists; /* per-target-table RETURNING tlists */
 	List	   *fdwPrivLists;	/* per-target-table FDW private data lists */
 	List	   *rowMarks;		/* PlanRowMarks (non-locking only) */