Do not write out WCOs in Query

The WithCheckOptions list in Query are only populated during rewrite and
do not need to be written out or read in as part of a Query structure.

Further, move WithCheckOptions to the bottom and add comments to clarify
that it is only populated during rewrite.

Back-patch to 9.5 with a catversion bump, as we are still in alpha.

src/backend/nodes/copyfuncs.c

@@ -2701,7 +2701,6 @@ _copyQuery(const Query *from)
 	COPY_NODE_FIELD(rtable);
 	COPY_NODE_FIELD(jointree);
 	COPY_NODE_FIELD(targetList);
-	COPY_NODE_FIELD(withCheckOptions);
 	COPY_NODE_FIELD(onConflict);
 	COPY_NODE_FIELD(returningList);
 	COPY_NODE_FIELD(groupClause);
@@ -2715,6 +2714,7 @@ _copyQuery(const Query *from)
 	COPY_NODE_FIELD(rowMarks);
 	COPY_NODE_FIELD(setOperations);
 	COPY_NODE_FIELD(constraintDeps);
+	COPY_NODE_FIELD(withCheckOptions);
 
 	return newnode;
 }

src/backend/nodes/equalfuncs.c

@@ -906,7 +906,6 @@ _equalQuery(const Query *a, const Query *b)
 	COMPARE_NODE_FIELD(rtable);
 	COMPARE_NODE_FIELD(jointree);
 	COMPARE_NODE_FIELD(targetList);
-	COMPARE_NODE_FIELD(withCheckOptions);
 	COMPARE_NODE_FIELD(onConflict);
 	COMPARE_NODE_FIELD(returningList);
 	COMPARE_NODE_FIELD(groupClause);
@@ -920,6 +919,7 @@ _equalQuery(const Query *a, const Query *b)
 	COMPARE_NODE_FIELD(rowMarks);
 	COMPARE_NODE_FIELD(setOperations);
 	COMPARE_NODE_FIELD(constraintDeps);
+	COMPARE_NODE_FIELD(withCheckOptions);
 
 	return true;
 }

src/backend/nodes/outfuncs.c

@@ -2379,7 +2379,6 @@ _outQuery(StringInfo str, const Query *node)
 	WRITE_NODE_FIELD(rtable);
 	WRITE_NODE_FIELD(jointree);
 	WRITE_NODE_FIELD(targetList);
-	WRITE_NODE_FIELD(withCheckOptions);
 	WRITE_NODE_FIELD(onConflict);
 	WRITE_NODE_FIELD(returningList);
 	WRITE_NODE_FIELD(groupClause);

src/backend/nodes/readfuncs.c

@@ -213,7 +213,6 @@ _readQuery(void)
 	READ_NODE_FIELD(rtable);
 	READ_NODE_FIELD(jointree);
 	READ_NODE_FIELD(targetList);
-	READ_NODE_FIELD(withCheckOptions);
 	READ_NODE_FIELD(onConflict);
 	READ_NODE_FIELD(returningList);
 	READ_NODE_FIELD(groupClause);

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201510041
+#define CATALOG_VERSION_NO	201510051
 
 #endif

src/include/nodes/parsenodes.h

@@ -130,8 +130,6 @@ typedef struct Query
 
 	List	   *targetList;		/* target list (of TargetEntry) */
 
-	List	   *withCheckOptions;		/* a list of WithCheckOption's */
-
 	OnConflictExpr *onConflict; /* ON CONFLICT DO [NOTHING | UPDATE] */
 
 	List	   *returningList;	/* return-values list (of TargetEntry) */
@@ -158,6 +156,10 @@ typedef struct Query
 
 	List	   *constraintDeps; /* a list of pg_constraint OIDs that the query
 								 * depends on to be semantically valid */
+
+	List	   *withCheckOptions;	/* a list of WithCheckOption's, which are
+									 * only added during rewrite and therefore
+									 * are not written out as part of Query. */
 } Query;