Separate parse-analysis for utility commands out of parser/analyze.c

(which now deals only in optimizable statements), and put that code
into a new file parser/parse_utilcmd.c.  This helps clarify and enforce
the design rule that utility statements shouldn't be processed during
the regular parse analysis phase; all interpretation of their meaning
should happen after they are given to ProcessUtility to execute.
(We need this because we don't retain any locks for a utility statement
that's in a plan cache, nor have any way to detect that it's stale.)

We are also able to simplify the API for parse_analyze() and related
routines, because they will now always return exactly one Query structure.

In passing, fix bug #3403 concerning trying to add a serial column to
an existing temp table (this is largely Heikki's work, but we needed
all that restructuring to make it safe).

1 files changed, 1800 insertions, 0 deletions

diff --git a/src/backend/parser/parse_utilcmd.c b/src/backend/parser/parse_utilcmd.c
new file mode 100644
index 00000000000..37822251943
--- /dev/null
+++ b/src/backend/parser/parse_utilcmd.c
@@ -0,0 +1,1800 @@
+/*-------------------------------------------------------------------------
+ *
+ * parse_utilcmd.c
+ *	  Perform parse analysis work for various utility commands
+ *
+ * Formerly we did this work during parse_analyze() in analyze.c.  However
+ * that is fairly unsafe in the presence of querytree caching, since any
+ * database state that we depend on in making the transformations might be
+ * obsolete by the time the utility command is executed; and utility commands
+ * have no infrastructure for holding locks or rechecking plan validity.
+ * Hence these functions are now called at the start of execution of their
+ * respective utility commands.
+ *
+ * NOTE: in general we must avoid scribbling on the passed-in raw parse
+ * tree, since it might be in a plan cache.  The simplest solution is
+ * a quick copyObject() call before manipulating the query tree.
+ *
+ *
+ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *	$PostgreSQL: pgsql/src/backend/parser/parse_utilcmd.c,v 2.1 2007/06/23 22:12:51 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/heap.h"
+#include "catalog/index.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_type.h"
+#include "commands/defrem.h"
+#include "commands/tablecmds.h"
+#include "miscadmin.h"
+#include "nodes/makefuncs.h"
+#include "optimizer/clauses.h"
+#include "parser/analyze.h"
+#include "parser/gramparse.h"
+#include "parser/parse_clause.h"
+#include "parser/parse_expr.h"
+#include "parser/parse_relation.h"
+#include "parser/parse_type.h"
+#include "parser/parse_utilcmd.h"
+#include "rewrite/rewriteManip.h"
+#include "utils/acl.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+
+
+/* State shared by transformCreateStmt and its subroutines */
+typedef struct
+{
+	const char *stmtType;		/* "CREATE TABLE" or "ALTER TABLE" */
+	RangeVar   *relation;		/* relation to create */
+	Relation	rel;			/* opened/locked rel, if ALTER */
+	List	   *inhRelations;	/* relations to inherit from */
+	bool		isalter;		/* true if altering existing table */
+	bool		hasoids;		/* does relation have an OID column? */
+	List	   *columns;		/* ColumnDef items */
+	List	   *ckconstraints;	/* CHECK constraints */
+	List	   *fkconstraints;	/* FOREIGN KEY constraints */
+	List	   *ixconstraints;	/* index-creating constraints */
+	List	   *blist;			/* "before list" of things to do before
+								 * creating the table */
+	List	   *alist;			/* "after list" of things to do after creating
+								 * the table */
+	IndexStmt  *pkey;			/* PRIMARY KEY index, if any */
+} CreateStmtContext;
+
+/* State shared by transformCreateSchemaStmt and its subroutines */
+typedef struct
+{
+	const char *stmtType;		/* "CREATE SCHEMA" or "ALTER SCHEMA" */
+	char	   *schemaname;		/* name of schema */
+	char	   *authid;			/* owner of schema */
+	List	   *sequences;		/* CREATE SEQUENCE items */
+	List	   *tables;			/* CREATE TABLE items */
+	List	   *views;			/* CREATE VIEW items */
+	List	   *indexes;		/* CREATE INDEX items */
+	List	   *triggers;		/* CREATE TRIGGER items */
+	List	   *grants;			/* GRANT items */
+} CreateSchemaStmtContext;
+
+
+static void transformColumnDefinition(ParseState *pstate,
+						  CreateStmtContext *cxt,
+						  ColumnDef *column);
+static void transformTableConstraint(ParseState *pstate,
+						 CreateStmtContext *cxt,
+						 Constraint *constraint);
+static void transformInhRelation(ParseState *pstate, CreateStmtContext *cxt,
+					 InhRelation *inhrelation);
+static void transformIndexConstraints(ParseState *pstate,
+						  CreateStmtContext *cxt);
+static void transformFKConstraints(ParseState *pstate,
+					   CreateStmtContext *cxt,
+					   bool skipValidation,
+					   bool isAddConstraint);
+static void transformConstraintAttrs(List *constraintList);
+static void transformColumnType(ParseState *pstate, ColumnDef *column);
+static void setSchemaName(char *context_schema, char **stmt_schema_name);
+
+
+/*
+ * transformCreateStmt -
+ *	  parse analysis for CREATE TABLE
+ *
+ * Returns a List of utility commands to be done in sequence.  One of these
+ * will be the transformed CreateStmt, but there may be additional actions
+ * to be done before and after the actual DefineRelation() call.
+ *
+ * SQL92 allows constraints to be scattered all over, so thumb through
+ * the columns and collect all constraints into one place.
+ * If there are any implied indices (e.g. UNIQUE or PRIMARY KEY)
+ * then expand those into multiple IndexStmt blocks.
+ *	  - thomas 1997-12-02
+ */
+List *
+transformCreateStmt(CreateStmt *stmt, const char *queryString)
+{
+	ParseState *pstate;
+	CreateStmtContext cxt;
+	List	   *result;
+	List	   *save_alist;
+	ListCell   *elements;
+
+	/*
+	 * We must not scribble on the passed-in CreateStmt, so copy it.  (This
+	 * is overkill, but easy.)
+	 */
+	stmt = (CreateStmt *) copyObject(stmt);
+
+	/* Set up pstate */
+	pstate = make_parsestate(NULL);
+	pstate->p_sourcetext = queryString;
+
+	cxt.stmtType = "CREATE TABLE";
+	cxt.relation = stmt->relation;
+	cxt.rel = NULL;
+	cxt.inhRelations = stmt->inhRelations;
+	cxt.isalter = false;
+	cxt.columns = NIL;
+	cxt.ckconstraints = NIL;
+	cxt.fkconstraints = NIL;
+	cxt.ixconstraints = NIL;
+	cxt.blist = NIL;
+	cxt.alist = NIL;
+	cxt.pkey = NULL;
+	cxt.hasoids = interpretOidsOption(stmt->options);
+
+	/*
+	 * Run through each primary element in the table creation clause. Separate
+	 * column defs from constraints, and do preliminary analysis.
+	 */
+	foreach(elements, stmt->tableElts)
+	{
+		Node	   *element = lfirst(elements);
+
+		switch (nodeTag(element))
+		{
+			case T_ColumnDef:
+				transformColumnDefinition(pstate, &cxt,
+										  (ColumnDef *) element);
+				break;
+
+			case T_Constraint:
+				transformTableConstraint(pstate, &cxt,
+										 (Constraint *) element);
+				break;
+
+			case T_FkConstraint:
+				/* No pre-transformation needed */
+				cxt.fkconstraints = lappend(cxt.fkconstraints, element);
+				break;
+
+			case T_InhRelation:
+				transformInhRelation(pstate, &cxt,
+									 (InhRelation *) element);
+				break;
+
+			default:
+				elog(ERROR, "unrecognized node type: %d",
+					 (int) nodeTag(element));
+				break;
+		}
+	}
+
+	/*
+	 * transformIndexConstraints wants cxt.alist to contain only index
+	 * statements, so transfer anything we already have into save_alist.
+	 */
+	save_alist = cxt.alist;
+	cxt.alist = NIL;
+
+	Assert(stmt->constraints == NIL);
+
+	/*
+	 * Postprocess constraints that give rise to index definitions.
+	 */
+	transformIndexConstraints(pstate, &cxt);
+
+	/*
+	 * Postprocess foreign-key constraints.
+	 */
+	transformFKConstraints(pstate, &cxt, true, false);
+
+	/*
+	 * Output results.
+	 */
+	stmt->tableElts = cxt.columns;
+	stmt->constraints = cxt.ckconstraints;
+
+	result = lappend(cxt.blist, stmt);
+	result = list_concat(result, cxt.alist);
+	result = list_concat(result, save_alist);
+
+	return result;
+}
+
+/*
+ * transformColumnDefinition -
+ *		transform a single ColumnDef within CREATE TABLE
+ *		Also used in ALTER TABLE ADD COLUMN
+ */
+static void
+transformColumnDefinition(ParseState *pstate, CreateStmtContext *cxt,
+						  ColumnDef *column)
+{
+	bool		is_serial;
+	bool		saw_nullable;
+	bool		saw_default;
+	Constraint *constraint;
+	ListCell   *clist;
+
+	cxt->columns = lappend(cxt->columns, column);
+
+	/* Check for SERIAL pseudo-types */
+	is_serial = false;
+	if (list_length(column->typename->names) == 1)
+	{
+		char	   *typname = strVal(linitial(column->typename->names));
+
+		if (strcmp(typname, "serial") == 0 ||
+			strcmp(typname, "serial4") == 0)
+		{
+			is_serial = true;
+			column->typename->names = NIL;
+			column->typename->typeid = INT4OID;
+		}
+		else if (strcmp(typname, "bigserial") == 0 ||
+				 strcmp(typname, "serial8") == 0)
+		{
+			is_serial = true;
+			column->typename->names = NIL;
+			column->typename->typeid = INT8OID;
+		}
+	}
+
+	/* Do necessary work on the column type declaration */
+	transformColumnType(pstate, column);
+
+	/* Special actions for SERIAL pseudo-types */
+	if (is_serial)
+	{
+		Oid			snamespaceid;
+		char	   *snamespace;
+		char	   *sname;
+		char	   *qstring;
+		A_Const    *snamenode;
+		FuncCall   *funccallnode;
+		CreateSeqStmt *seqstmt;
+		AlterSeqStmt *altseqstmt;
+		List	   *attnamelist;
+
+		/*
+		 * Determine namespace and name to use for the sequence.
+		 *
+		 * Although we use ChooseRelationName, it's not guaranteed that the
+		 * selected sequence name won't conflict; given sufficiently long
+		 * field names, two different serial columns in the same table could
+		 * be assigned the same sequence name, and we'd not notice since we
+		 * aren't creating the sequence quite yet.  In practice this seems
+		 * quite unlikely to be a problem, especially since few people would
+		 * need two serial columns in one table.
+		 */
+		if (cxt->rel)
+			snamespaceid = RelationGetNamespace(cxt->rel);
+		else
+			snamespaceid = RangeVarGetCreationNamespace(cxt->relation);
+		snamespace = get_namespace_name(snamespaceid);
+		sname = ChooseRelationName(cxt->relation->relname,
+								   column->colname,
+								   "seq",
+								   snamespaceid);
+
+		ereport(NOTICE,
+				(errmsg("%s will create implicit sequence \"%s\" for serial column \"%s.%s\"",
+						cxt->stmtType, sname,
+						cxt->relation->relname, column->colname)));
+
+		/*
+		 * Build a CREATE SEQUENCE command to create the sequence object, and
+		 * add it to the list of things to be done before this CREATE/ALTER
+		 * TABLE.
+		 */
+		seqstmt = makeNode(CreateSeqStmt);
+		seqstmt->sequence = makeRangeVar(snamespace, sname);
+		seqstmt->options = NIL;
+
+		cxt->blist = lappend(cxt->blist, seqstmt);
+
+		/*
+		 * Build an ALTER SEQUENCE ... OWNED BY command to mark the sequence
+		 * as owned by this column, and add it to the list of things to be
+		 * done after this CREATE/ALTER TABLE.
+		 */
+		altseqstmt = makeNode(AlterSeqStmt);
+		altseqstmt->sequence = makeRangeVar(snamespace, sname);
+		attnamelist = list_make3(makeString(snamespace),
+								 makeString(cxt->relation->relname),
+								 makeString(column->colname));
+		altseqstmt->options = list_make1(makeDefElem("owned_by",
+													 (Node *) attnamelist));
+
+		cxt->alist = lappend(cxt->alist, altseqstmt);
+
+		/*
+		 * Create appropriate constraints for SERIAL.  We do this in full,
+		 * rather than shortcutting, so that we will detect any conflicting
+		 * constraints the user wrote (like a different DEFAULT).
+		 *
+		 * Create an expression tree representing the function call
+		 * nextval('sequencename').  We cannot reduce the raw tree to cooked
+		 * form until after the sequence is created, but there's no need to do
+		 * so.
+		 */
+		qstring = quote_qualified_identifier(snamespace, sname);
+		snamenode = makeNode(A_Const);
+		snamenode->val.type = T_String;
+		snamenode->val.val.str = qstring;
+		snamenode->typename = SystemTypeName("regclass");
+		funccallnode = makeNode(FuncCall);
+		funccallnode->funcname = SystemFuncName("nextval");
+		funccallnode->args = list_make1(snamenode);
+		funccallnode->agg_star = false;
+		funccallnode->agg_distinct = false;
+		funccallnode->location = -1;
+
+		constraint = makeNode(Constraint);
+		constraint->contype = CONSTR_DEFAULT;
+		constraint->raw_expr = (Node *) funccallnode;
+		constraint->cooked_expr = NULL;
+		constraint->keys = NIL;
+		column->constraints = lappend(column->constraints, constraint);
+
+		constraint = makeNode(Constraint);
+		constraint->contype = CONSTR_NOTNULL;
+		column->constraints = lappend(column->constraints, constraint);
+	}
+
+	/* Process column constraints, if any... */
+	transformConstraintAttrs(column->constraints);
+
+	saw_nullable = false;
+	saw_default = false;
+
+	foreach(clist, column->constraints)
+	{
+		constraint = lfirst(clist);
+
+		/*
+		 * If this column constraint is a FOREIGN KEY constraint, then we fill
+		 * in the current attribute's name and throw it into the list of FK
+		 * constraints to be processed later.
+		 */
+		if (IsA(constraint, FkConstraint))
+		{
+			FkConstraint *fkconstraint = (FkConstraint *) constraint;
+
+			fkconstraint->fk_attrs = list_make1(makeString(column->colname));
+			cxt->fkconstraints = lappend(cxt->fkconstraints, fkconstraint);
+			continue;
+		}
+
+		Assert(IsA(constraint, Constraint));
+
+		switch (constraint->contype)
+		{
+			case CONSTR_NULL:
+				if (saw_nullable && column->is_not_null)
+					ereport(ERROR,
+							(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("conflicting NULL/NOT NULL declarations for column \"%s\" of table \"%s\"",
+								  column->colname, cxt->relation->relname)));
+				column->is_not_null = FALSE;
+				saw_nullable = true;
+				break;
+
+			case CONSTR_NOTNULL:
+				if (saw_nullable && !column->is_not_null)
+					ereport(ERROR,
+							(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("conflicting NULL/NOT NULL declarations for column \"%s\" of table \"%s\"",
+								  column->colname, cxt->relation->relname)));
+				column->is_not_null = TRUE;
+				saw_nullable = true;
+				break;
+
+			case CONSTR_DEFAULT:
+				if (saw_default)
+					ereport(ERROR,
+							(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("multiple default values specified for column \"%s\" of table \"%s\"",
+								  column->colname, cxt->relation->relname)));
+				/* Note: DEFAULT NULL maps to constraint->raw_expr == NULL */
+				column->raw_default = constraint->raw_expr;
+				Assert(constraint->cooked_expr == NULL);
+				saw_default = true;
+				break;
+
+			case CONSTR_PRIMARY:
+			case CONSTR_UNIQUE:
+				if (constraint->keys == NIL)
+					constraint->keys = list_make1(makeString(column->colname));
+				cxt->ixconstraints = lappend(cxt->ixconstraints, constraint);
+				break;
+
+			case CONSTR_CHECK:
+				cxt->ckconstraints = lappend(cxt->ckconstraints, constraint);
+				break;
+
+			case CONSTR_ATTR_DEFERRABLE:
+			case CONSTR_ATTR_NOT_DEFERRABLE:
+			case CONSTR_ATTR_DEFERRED:
+			case CONSTR_ATTR_IMMEDIATE:
+				/* transformConstraintAttrs took care of these */
+				break;
+
+			default:
+				elog(ERROR, "unrecognized constraint type: %d",
+					 constraint->contype);
+				break;
+		}
+	}
+}
+
+/*
+ * transformTableConstraint
+ *		transform a Constraint node within CREATE TABLE or ALTER TABLE
+ */
+static void
+transformTableConstraint(ParseState *pstate, CreateStmtContext *cxt,
+						 Constraint *constraint)
+{
+	switch (constraint->contype)
+	{
+		case CONSTR_PRIMARY:
+		case CONSTR_UNIQUE:
+			cxt->ixconstraints = lappend(cxt->ixconstraints, constraint);
+			break;
+
+		case CONSTR_CHECK:
+			cxt->ckconstraints = lappend(cxt->ckconstraints, constraint);
+			break;
+
+		case CONSTR_NULL:
+		case CONSTR_NOTNULL:
+		case CONSTR_DEFAULT:
+		case CONSTR_ATTR_DEFERRABLE:
+		case CONSTR_ATTR_NOT_DEFERRABLE:
+		case CONSTR_ATTR_DEFERRED:
+		case CONSTR_ATTR_IMMEDIATE:
+			elog(ERROR, "invalid context for constraint type %d",
+				 constraint->contype);
+			break;
+
+		default:
+			elog(ERROR, "unrecognized constraint type: %d",
+				 constraint->contype);
+			break;
+	}
+}
+
+/*
+ * transformInhRelation
+ *
+ * Change the LIKE <subtable> portion of a CREATE TABLE statement into
+ * column definitions which recreate the user defined column portions of
+ * <subtable>.
+ */
+static void
+transformInhRelation(ParseState *pstate, CreateStmtContext *cxt,
+					 InhRelation *inhRelation)
+{
+	AttrNumber	parent_attno;
+	Relation	relation;
+	TupleDesc	tupleDesc;
+	TupleConstr *constr;
+	AclResult	aclresult;
+	bool		including_defaults = false;
+	bool		including_constraints = false;
+	bool		including_indexes = false;
+	ListCell   *elem;
+
+	relation = heap_openrv(inhRelation->relation, AccessShareLock);
+
+	if (relation->rd_rel->relkind != RELKIND_RELATION)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("inherited relation \"%s\" is not a table",
+						inhRelation->relation->relname)));
+
+	/*
+	 * Check for SELECT privilages
+	 */
+	aclresult = pg_class_aclcheck(RelationGetRelid(relation), GetUserId(),
+								  ACL_SELECT);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, ACL_KIND_CLASS,
+					   RelationGetRelationName(relation));
+
+	tupleDesc = RelationGetDescr(relation);
+	constr = tupleDesc->constr;
+
+	foreach(elem, inhRelation->options)
+	{
+		int			option = lfirst_int(elem);
+
+		switch (option)
+		{
+			case CREATE_TABLE_LIKE_INCLUDING_DEFAULTS:
+				including_defaults = true;
+				break;
+			case CREATE_TABLE_LIKE_EXCLUDING_DEFAULTS:
+				including_defaults = false;
+				break;
+			case CREATE_TABLE_LIKE_INCLUDING_CONSTRAINTS:
+				including_constraints = true;
+				break;
+			case CREATE_TABLE_LIKE_EXCLUDING_CONSTRAINTS:
+				including_constraints = false;
+				break;
+			case CREATE_TABLE_LIKE_INCLUDING_INDEXES:
+				including_indexes = true;
+				break;
+			case CREATE_TABLE_LIKE_EXCLUDING_INDEXES:
+				including_indexes = false;
+				break;
+			default:
+				elog(ERROR, "unrecognized CREATE TABLE LIKE option: %d",
+					 option);
+		}
+	}
+
+	if (including_indexes)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("LIKE INCLUDING INDEXES is not implemented")));
+
+	/*
+	 * Insert the copied attributes into the cxt for the new table
+	 * definition.
+	 */
+	for (parent_attno = 1; parent_attno <= tupleDesc->natts;
+		 parent_attno++)
+	{
+		Form_pg_attribute attribute = tupleDesc->attrs[parent_attno - 1];
+		char	   *attributeName = NameStr(attribute->attname);
+		ColumnDef  *def;
+
+		/*
+		 * Ignore dropped columns in the parent.
+		 */
+		if (attribute->attisdropped)
+			continue;
+
+		/*
+		 * Create a new column, which is marked as NOT inherited.
+		 *
+		 * For constraints, ONLY the NOT NULL constraint is inherited by the
+		 * new column definition per SQL99.
+		 */
+		def = makeNode(ColumnDef);
+		def->colname = pstrdup(attributeName);
+		def->typename = makeTypeNameFromOid(attribute->atttypid,
+											attribute->atttypmod);
+		def->inhcount = 0;
+		def->is_local = true;
+		def->is_not_null = attribute->attnotnull;
+		def->raw_default = NULL;
+		def->cooked_default = NULL;
+		def->constraints = NIL;
+
+		/*
+		 * Add to column list
+		 */
+		cxt->columns = lappend(cxt->columns, def);
+
+		/*
+		 * Copy default, if present and the default has been requested
+		 */
+		if (attribute->atthasdef && including_defaults)
+		{
+			char	   *this_default = NULL;
+			AttrDefault *attrdef;
+			int			i;
+
+			/* Find default in constraint structure */
+			Assert(constr != NULL);
+			attrdef = constr->defval;
+			for (i = 0; i < constr->num_defval; i++)
+			{
+				if (attrdef[i].adnum == parent_attno)
+				{
+					this_default = attrdef[i].adbin;
+					break;
+				}
+			}
+			Assert(this_default != NULL);
+
+			/*
+			 * If default expr could contain any vars, we'd need to fix 'em,
+			 * but it can't; so default is ready to apply to child.
+			 */
+
+			def->cooked_default = pstrdup(this_default);
+		}
+	}
+
+	/*
+	 * Copy CHECK constraints if requested, being careful to adjust
+	 * attribute numbers
+	 */
+	if (including_constraints && tupleDesc->constr)
+	{
+		AttrNumber *attmap = varattnos_map_schema(tupleDesc, cxt->columns);
+		int			ccnum;
+
+		for (ccnum = 0; ccnum < tupleDesc->constr->num_check; ccnum++)
+		{
+			char	   *ccname = tupleDesc->constr->check[ccnum].ccname;
+			char	   *ccbin = tupleDesc->constr->check[ccnum].ccbin;
+			Node	   *ccbin_node = stringToNode(ccbin);
+			Constraint *n = makeNode(Constraint);
+
+			change_varattnos_of_a_node(ccbin_node, attmap);
+
+			n->contype = CONSTR_CHECK;
+			n->name = pstrdup(ccname);
+			n->raw_expr = NULL;
+			n->cooked_expr = nodeToString(ccbin_node);
+			n->indexspace = NULL;
+			cxt->ckconstraints = lappend(cxt->ckconstraints, (Node *) n);
+		}
+	}
+
+	/*
+	 * Close the parent rel, but keep our AccessShareLock on it until xact
+	 * commit.	That will prevent someone else from deleting or ALTERing the
+	 * parent before the child is committed.
+	 */
+	heap_close(relation, NoLock);
+}
+
+/*
+ * transformIndexConstraints
+ *		Handle UNIQUE and PRIMARY KEY constraints, which create indexes
+ */
+static void
+transformIndexConstraints(ParseState *pstate, CreateStmtContext *cxt)
+{
+	IndexStmt  *index;
+	List	   *indexlist = NIL;
+	ListCell   *listptr;
+	ListCell   *l;
+
+	/*
+	 * Run through the constraints that need to generate an index. For PRIMARY
+	 * KEY, mark each column as NOT NULL and create an index. For UNIQUE,
+	 * create an index as for PRIMARY KEY, but do not insist on NOT NULL.
+	 */
+	foreach(listptr, cxt->ixconstraints)
+	{
+		Constraint *constraint = lfirst(listptr);
+		ListCell   *keys;
+		IndexElem  *iparam;
+
+		Assert(IsA(constraint, Constraint));
+		Assert((constraint->contype == CONSTR_PRIMARY)
+			   || (constraint->contype == CONSTR_UNIQUE));
+
+		index = makeNode(IndexStmt);
+
+		index->unique = true;
+		index->primary = (constraint->contype == CONSTR_PRIMARY);
+		if (index->primary)
+		{
+			if (cxt->pkey != NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+						 errmsg("multiple primary keys for table \"%s\" are not allowed",
+								cxt->relation->relname)));
+			cxt->pkey = index;
+
+			/*
+			 * In ALTER TABLE case, a primary index might already exist, but
+			 * DefineIndex will check for it.
+			 */
+		}
+		index->isconstraint = true;
+
+		if (constraint->name != NULL)
+			index->idxname = pstrdup(constraint->name);
+		else
+			index->idxname = NULL;		/* DefineIndex will choose name */
+
+		index->relation = cxt->relation;
+		index->accessMethod = DEFAULT_INDEX_TYPE;
+		index->options = constraint->options;
+		index->tableSpace = constraint->indexspace;
+		index->indexParams = NIL;
+		index->whereClause = NULL;
+		index->concurrent = false;
+
+		/*
+		 * Make sure referenced keys exist.  If we are making a PRIMARY KEY
+		 * index, also make sure they are NOT NULL, if possible. (Although we
+		 * could leave it to DefineIndex to mark the columns NOT NULL, it's
+		 * more efficient to get it right the first time.)
+		 */
+		foreach(keys, constraint->keys)
+		{
+			char	   *key = strVal(lfirst(keys));
+			bool		found = false;
+			ColumnDef  *column = NULL;
+			ListCell   *columns;
+
+			foreach(columns, cxt->columns)
+			{
+				column = (ColumnDef *) lfirst(columns);
+				Assert(IsA(column, ColumnDef));
+				if (strcmp(column->colname, key) == 0)
+				{
+					found = true;
+					break;
+				}
+			}
+			if (found)
+			{
+				/* found column in the new table; force it to be NOT NULL */
+				if (constraint->contype == CONSTR_PRIMARY)
+					column->is_not_null = TRUE;
+			}
+			else if (SystemAttributeByName(key, cxt->hasoids) != NULL)
+			{
+				/*
+				 * column will be a system column in the new table, so accept
+				 * it.	System columns can't ever be null, so no need to worry
+				 * about PRIMARY/NOT NULL constraint.
+				 */
+				found = true;
+			}
+			else if (cxt->inhRelations)
+			{
+				/* try inherited tables */
+				ListCell   *inher;
+
+				foreach(inher, cxt->inhRelations)
+				{
+					RangeVar   *inh = (RangeVar *) lfirst(inher);
+					Relation	rel;
+					int			count;
+
+					Assert(IsA(inh, RangeVar));
+					rel = heap_openrv(inh, AccessShareLock);
+					if (rel->rd_rel->relkind != RELKIND_RELATION)
+						ereport(ERROR,
+								(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+						   errmsg("inherited relation \"%s\" is not a table",
+								  inh->relname)));
+					for (count = 0; count < rel->rd_att->natts; count++)
+					{
+						Form_pg_attribute inhattr = rel->rd_att->attrs[count];
+						char	   *inhname = NameStr(inhattr->attname);
+
+						if (inhattr->attisdropped)
+							continue;
+						if (strcmp(key, inhname) == 0)
+						{
+							found = true;
+
+							/*
+							 * We currently have no easy way to force an
+							 * inherited column to be NOT NULL at creation, if
+							 * its parent wasn't so already. We leave it to
+							 * DefineIndex to fix things up in this case.
+							 */
+							break;
+						}
+					}
+					heap_close(rel, NoLock);
+					if (found)
+						break;
+				}
+			}
+
+			/*
+			 * In the ALTER TABLE case, don't complain about index keys not
+			 * created in the command; they may well exist already.
+			 * DefineIndex will complain about them if not, and will also take
+			 * care of marking them NOT NULL.
+			 */
+			if (!found && !cxt->isalter)
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_COLUMN),
+						 errmsg("column \"%s\" named in key does not exist",
+								key)));
+
+			/* Check for PRIMARY KEY(foo, foo) */
+			foreach(columns, index->indexParams)
+			{
+				iparam = (IndexElem *) lfirst(columns);
+				if (iparam->name && strcmp(key, iparam->name) == 0)
+				{
+					if (index->primary)
+						ereport(ERROR,
+								(errcode(ERRCODE_DUPLICATE_COLUMN),
+								 errmsg("column \"%s\" appears twice in primary key constraint",
+										key)));
+					else
+						ereport(ERROR,
+								(errcode(ERRCODE_DUPLICATE_COLUMN),
+								 errmsg("column \"%s\" appears twice in unique constraint",
+										key)));
+				}
+			}
+
+			/* OK, add it to the index definition */
+			iparam = makeNode(IndexElem);
+			iparam->name = pstrdup(key);
+			iparam->expr = NULL;
+			iparam->opclass = NIL;
+			iparam->ordering = SORTBY_DEFAULT;
+			iparam->nulls_ordering = SORTBY_NULLS_DEFAULT;
+			index->indexParams = lappend(index->indexParams, iparam);
+		}
+
+		indexlist = lappend(indexlist, index);
+	}
+
+	/*
+	 * Scan the index list and remove any redundant index specifications. This
+	 * can happen if, for instance, the user writes UNIQUE PRIMARY KEY. A
+	 * strict reading of SQL92 would suggest raising an error instead, but
+	 * that strikes me as too anal-retentive. - tgl 2001-02-14
+	 *
+	 * XXX in ALTER TABLE case, it'd be nice to look for duplicate
+	 * pre-existing indexes, too.
+	 */
+	Assert(cxt->alist == NIL);
+	if (cxt->pkey != NULL)
+	{
+		/* Make sure we keep the PKEY index in preference to others... */
+		cxt->alist = list_make1(cxt->pkey);
+	}
+
+	foreach(l, indexlist)
+	{
+		bool		keep = true;
+		ListCell   *k;
+
+		index = lfirst(l);
+
+		/* if it's pkey, it's already in cxt->alist */
+		if (index == cxt->pkey)
+			continue;
+
+		foreach(k, cxt->alist)
+		{
+			IndexStmt  *priorindex = lfirst(k);
+
+			if (equal(index->indexParams, priorindex->indexParams))
+			{
+				/*
+				 * If the prior index is as yet unnamed, and this one is
+				 * named, then transfer the name to the prior index. This
+				 * ensures that if we have named and unnamed constraints,
+				 * we'll use (at least one of) the names for the index.
+				 */
+				if (priorindex->idxname == NULL)
+					priorindex->idxname = index->idxname;
+				keep = false;
+				break;
+			}
+		}
+
+		if (keep)
+			cxt->alist = lappend(cxt->alist, index);
+	}
+}
+
+/*
+ * transformFKConstraints
+ *		handle FOREIGN KEY constraints
+ */
+static void
+transformFKConstraints(ParseState *pstate, CreateStmtContext *cxt,
+					   bool skipValidation, bool isAddConstraint)
+{
+	ListCell   *fkclist;
+
+	if (cxt->fkconstraints == NIL)
+		return;
+
+	/*
+	 * If CREATE TABLE or adding a column with NULL default, we can safely
+	 * skip validation of the constraint.
+	 */
+	if (skipValidation)
+	{
+		foreach(fkclist, cxt->fkconstraints)
+		{
+			FkConstraint *fkconstraint = (FkConstraint *) lfirst(fkclist);
+
+			fkconstraint->skip_validation = true;
+		}
+	}
+
+	/*
+	 * For CREATE TABLE or ALTER TABLE ADD COLUMN, gin up an ALTER TABLE ADD
+	 * CONSTRAINT command to execute after the basic command is complete. (If
+	 * called from ADD CONSTRAINT, that routine will add the FK constraints to
+	 * its own subcommand list.)
+	 *
+	 * Note: the ADD CONSTRAINT command must also execute after any index
+	 * creation commands.  Thus, this should run after
+	 * transformIndexConstraints, so that the CREATE INDEX commands are
+	 * already in cxt->alist.
+	 */
+	if (!isAddConstraint)
+	{
+		AlterTableStmt *alterstmt = makeNode(AlterTableStmt);
+
+		alterstmt->relation = cxt->relation;
+		alterstmt->cmds = NIL;
+		alterstmt->relkind = OBJECT_TABLE;
+
+		foreach(fkclist, cxt->fkconstraints)
+		{
+			FkConstraint *fkconstraint = (FkConstraint *) lfirst(fkclist);
+			AlterTableCmd *altercmd = makeNode(AlterTableCmd);
+
+			altercmd->subtype = AT_ProcessedConstraint;
+			altercmd->name = NULL;
+			altercmd->def = (Node *) fkconstraint;
+			alterstmt->cmds = lappend(alterstmt->cmds, altercmd);
+		}
+
+		cxt->alist = lappend(cxt->alist, alterstmt);
+	}
+}
+
+/*
+ * transformIndexStmt - parse analysis for CREATE INDEX
+ *
+ * Note: this is a no-op for an index not using either index expressions or
+ * a predicate expression.  There are several code paths that create indexes
+ * without bothering to call this, because they know they don't have any
+ * such expressions to deal with.
+ */
+IndexStmt *
+transformIndexStmt(IndexStmt *stmt, const char *queryString)
+{
+	Relation	rel;
+	ParseState *pstate;
+	RangeTblEntry *rte;
+	ListCell   *l;
+
+	/*
+	 * We must not scribble on the passed-in IndexStmt, so copy it.  (This
+	 * is overkill, but easy.)
+	 */
+	stmt = (IndexStmt *) copyObject(stmt);
+
+	/*
+	 * Open the parent table with appropriate locking.  We must do this
+	 * because addRangeTableEntry() would acquire only AccessShareLock,
+	 * leaving DefineIndex() needing to do a lock upgrade with consequent
+	 * risk of deadlock.  Make sure this stays in sync with the type of
+	 * lock DefineIndex() wants.
+	 */
+	rel = heap_openrv(stmt->relation,
+				(stmt->concurrent ? ShareUpdateExclusiveLock : ShareLock));
+
+	/* Set up pstate */
+	pstate = make_parsestate(NULL);
+	pstate->p_sourcetext = queryString;
+
+	/*
+	 * Put the parent table into the rtable so that the expressions can
+	 * refer to its fields without qualification.
+	 */
+	rte = addRangeTableEntry(pstate, stmt->relation, NULL, false, true);
+
+	/* no to join list, yes to namespaces */
+	addRTEtoQuery(pstate, rte, false, true, true);
+
+	/* take care of the where clause */
+	if (stmt->whereClause)
+		stmt->whereClause = transformWhereClause(pstate,
+												 stmt->whereClause,
+												 "WHERE");
+
+	/* take care of any index expressions */
+	foreach(l, stmt->indexParams)
+	{
+		IndexElem  *ielem = (IndexElem *) lfirst(l);
+
+		if (ielem->expr)
+		{
+			ielem->expr = transformExpr(pstate, ielem->expr);
+
+			/*
+			 * We check only that the result type is legitimate; this is for
+			 * consistency with what transformWhereClause() checks for the
+			 * predicate.  DefineIndex() will make more checks.
+			 */
+			if (expression_returns_set(ielem->expr))
+				ereport(ERROR,
+						(errcode(ERRCODE_DATATYPE_MISMATCH),
+						 errmsg("index expression cannot return a set")));
+		}
+	}
+
+	/*
+	 * Check that only the base rel is mentioned.
+	 */
+	if (list_length(pstate->p_rtable) != 1)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+				 errmsg("index expressions and predicates can refer only to the table being indexed")));
+
+	free_parsestate(pstate);
+
+	/* Close relation, but keep the lock */
+	heap_close(rel, NoLock);
+
+	return stmt;
+}
+
+
+/*
+ * transformRuleStmt -
+ *	  transform a CREATE RULE Statement. The action is a list of parse
+ *	  trees which is transformed into a list of query trees, and we also
+ *	  transform the WHERE clause if any.
+ *
+ * actions and whereClause are output parameters that receive the
+ * transformed results.
+ *
+ * Note that we must not scribble on the passed-in RuleStmt, so we do
+ * copyObject() on the actions and WHERE clause.
+ */
+void
+transformRuleStmt(RuleStmt *stmt, const char *queryString,
+				  List **actions, Node **whereClause)
+{
+	Relation	rel;
+	ParseState *pstate;
+	RangeTblEntry *oldrte;
+	RangeTblEntry *newrte;
+
+	/*
+	 * To avoid deadlock, make sure the first thing we do is grab
+	 * AccessExclusiveLock on the target relation.	This will be needed by
+	 * DefineQueryRewrite(), and we don't want to grab a lesser lock
+	 * beforehand.
+	 */
+	rel = heap_openrv(stmt->relation, AccessExclusiveLock);
+
+	/* Set up pstate */
+	pstate = make_parsestate(NULL);
+	pstate->p_sourcetext = queryString;
+
+	/*
+	 * NOTE: 'OLD' must always have a varno equal to 1 and 'NEW' equal to 2.
+	 * Set up their RTEs in the main pstate for use in parsing the rule
+	 * qualification.
+	 */
+	oldrte = addRangeTableEntryForRelation(pstate, rel,
+										   makeAlias("*OLD*", NIL),
+										   false, false);
+	newrte = addRangeTableEntryForRelation(pstate, rel,
+										   makeAlias("*NEW*", NIL),
+										   false, false);
+	/* Must override addRangeTableEntry's default access-check flags */
+	oldrte->requiredPerms = 0;
+	newrte->requiredPerms = 0;
+
+	/*
+	 * They must be in the namespace too for lookup purposes, but only add the
+	 * one(s) that are relevant for the current kind of rule.  In an UPDATE
+	 * rule, quals must refer to OLD.field or NEW.field to be unambiguous, but
+	 * there's no need to be so picky for INSERT & DELETE.  We do not add them
+	 * to the joinlist.
+	 */
+	switch (stmt->event)
+	{
+		case CMD_SELECT:
+			addRTEtoQuery(pstate, oldrte, false, true, true);
+			break;
+		case CMD_UPDATE:
+			addRTEtoQuery(pstate, oldrte, false, true, true);
+			addRTEtoQuery(pstate, newrte, false, true, true);
+			break;
+		case CMD_INSERT:
+			addRTEtoQuery(pstate, newrte, false, true, true);
+			break;
+		case CMD_DELETE:
+			addRTEtoQuery(pstate, oldrte, false, true, true);
+			break;
+		default:
+			elog(ERROR, "unrecognized event type: %d",
+				 (int) stmt->event);
+			break;
+	}
+
+	/* take care of the where clause */
+	*whereClause = transformWhereClause(pstate,
+										(Node *) copyObject(stmt->whereClause),
+										"WHERE");
+
+	if (list_length(pstate->p_rtable) != 2)		/* naughty, naughty... */
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("rule WHERE condition cannot contain references to other relations")));
+
+	/* aggregates not allowed (but subselects are okay) */
+	if (pstate->p_hasAggs)
+		ereport(ERROR,
+				(errcode(ERRCODE_GROUPING_ERROR),
+		   errmsg("cannot use aggregate function in rule WHERE condition")));
+
+	/*
+	 * 'instead nothing' rules with a qualification need a query rangetable so
+	 * the rewrite handler can add the negated rule qualification to the
+	 * original query. We create a query with the new command type CMD_NOTHING
+	 * here that is treated specially by the rewrite system.
+	 */
+	if (stmt->actions == NIL)
+	{
+		Query	   *nothing_qry = makeNode(Query);
+
+		nothing_qry->commandType = CMD_NOTHING;
+		nothing_qry->rtable = pstate->p_rtable;
+		nothing_qry->jointree = makeFromExpr(NIL, NULL); /* no join wanted */
+
+		*actions = list_make1(nothing_qry);
+	}
+	else
+	{
+		ListCell   *l;
+		List	   *newactions = NIL;
+
+		/*
+		 * transform each statement, like parse_sub_analyze()
+		 */
+		foreach(l, stmt->actions)
+		{
+			Node	   *action = (Node *) lfirst(l);
+			ParseState *sub_pstate = make_parsestate(NULL);
+			Query	   *sub_qry,
+					   *top_subqry;
+			bool		has_old,
+						has_new;
+
+			/*
+			 * Since outer ParseState isn't parent of inner, have to pass
+			 * down the query text by hand.
+			 */
+			sub_pstate->p_sourcetext = queryString;
+
+			/*
+			 * Set up OLD/NEW in the rtable for this statement.  The entries
+			 * are added only to relnamespace, not varnamespace, because we
+			 * don't want them to be referred to by unqualified field names
+			 * nor "*" in the rule actions.  We decide later whether to put
+			 * them in the joinlist.
+			 */
+			oldrte = addRangeTableEntryForRelation(sub_pstate, rel,
+												   makeAlias("*OLD*", NIL),
+												   false, false);
+			newrte = addRangeTableEntryForRelation(sub_pstate, rel,
+												   makeAlias("*NEW*", NIL),
+												   false, false);
+			oldrte->requiredPerms = 0;
+			newrte->requiredPerms = 0;
+			addRTEtoQuery(sub_pstate, oldrte, false, true, false);
+			addRTEtoQuery(sub_pstate, newrte, false, true, false);
+
+			/* Transform the rule action statement */
+			top_subqry = transformStmt(sub_pstate,
+									   (Node *) copyObject(action));
+
+			/*
+			 * We cannot support utility-statement actions (eg NOTIFY) with
+			 * nonempty rule WHERE conditions, because there's no way to make
+			 * the utility action execute conditionally.
+			 */
+			if (top_subqry->commandType == CMD_UTILITY &&
+				*whereClause != NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("rules with WHERE conditions can only have SELECT, INSERT, UPDATE, or DELETE actions")));
+
+			/*
+			 * If the action is INSERT...SELECT, OLD/NEW have been pushed down
+			 * into the SELECT, and that's what we need to look at. (Ugly
+			 * kluge ... try to fix this when we redesign querytrees.)
+			 */
+			sub_qry = getInsertSelectQuery(top_subqry, NULL);
+
+			/*
+			 * If the sub_qry is a setop, we cannot attach any qualifications
+			 * to it, because the planner won't notice them.  This could
+			 * perhaps be relaxed someday, but for now, we may as well reject
+			 * such a rule immediately.
+			 */
+			if (sub_qry->setOperations != NULL && *whereClause != NULL)
+				ereport(ERROR,
+						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						 errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
+
+			/*
+			 * Validate action's use of OLD/NEW, qual too
+			 */
+			has_old =
+				rangeTableEntry_used((Node *) sub_qry, PRS2_OLD_VARNO, 0) ||
+				rangeTableEntry_used(*whereClause, PRS2_OLD_VARNO, 0);
+			has_new =
+				rangeTableEntry_used((Node *) sub_qry, PRS2_NEW_VARNO, 0) ||
+				rangeTableEntry_used(*whereClause, PRS2_NEW_VARNO, 0);
+
+			switch (stmt->event)
+			{
+				case CMD_SELECT:
+					if (has_old)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+								 errmsg("ON SELECT rule cannot use OLD")));
+					if (has_new)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+								 errmsg("ON SELECT rule cannot use NEW")));
+					break;
+				case CMD_UPDATE:
+					/* both are OK */
+					break;
+				case CMD_INSERT:
+					if (has_old)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+								 errmsg("ON INSERT rule cannot use OLD")));
+					break;
+				case CMD_DELETE:
+					if (has_new)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+								 errmsg("ON DELETE rule cannot use NEW")));
+					break;
+				default:
+					elog(ERROR, "unrecognized event type: %d",
+						 (int) stmt->event);
+					break;
+			}
+
+			/*
+			 * For efficiency's sake, add OLD to the rule action's jointree
+			 * only if it was actually referenced in the statement or qual.
+			 *
+			 * For INSERT, NEW is not really a relation (only a reference to
+			 * the to-be-inserted tuple) and should never be added to the
+			 * jointree.
+			 *
+			 * For UPDATE, we treat NEW as being another kind of reference to
+			 * OLD, because it represents references to *transformed* tuples
+			 * of the existing relation.  It would be wrong to enter NEW
+			 * separately in the jointree, since that would cause a double
+			 * join of the updated relation.  It's also wrong to fail to make
+			 * a jointree entry if only NEW and not OLD is mentioned.
+			 */
+			if (has_old || (has_new && stmt->event == CMD_UPDATE))
+			{
+				/*
+				 * If sub_qry is a setop, manipulating its jointree will do no
+				 * good at all, because the jointree is dummy. (This should be
+				 * a can't-happen case because of prior tests.)
+				 */
+				if (sub_qry->setOperations != NULL)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("conditional UNION/INTERSECT/EXCEPT statements are not implemented")));
+				/* hack so we can use addRTEtoQuery() */
+				sub_pstate->p_rtable = sub_qry->rtable;
+				sub_pstate->p_joinlist = sub_qry->jointree->fromlist;
+				addRTEtoQuery(sub_pstate, oldrte, true, false, false);
+				sub_qry->jointree->fromlist = sub_pstate->p_joinlist;
+			}
+
+			newactions = lappend(newactions, top_subqry);
+
+			free_parsestate(sub_pstate);
+		}
+
+		*actions = newactions;
+	}
+
+	free_parsestate(pstate);
+
+	/* Close relation, but keep the exclusive lock */
+	heap_close(rel, NoLock);
+}
+
+
+/*
+ * transformAlterTableStmt -
+ *		parse analysis for ALTER TABLE
+ *
+ * Returns a List of utility commands to be done in sequence.  One of these
+ * will be the transformed AlterTableStmt, but there may be additional actions
+ * to be done before and after the actual AlterTable() call.
+ */
+List *
+transformAlterTableStmt(AlterTableStmt *stmt, const char *queryString)
+{
+	Relation	rel;
+	ParseState *pstate;
+	CreateStmtContext cxt;
+	List	   *result;
+	List	   *save_alist;
+	ListCell   *lcmd,
+			   *l;
+	List	   *newcmds = NIL;
+	bool		skipValidation = true;
+	AlterTableCmd *newcmd;
+
+	/*
+	 * We must not scribble on the passed-in AlterTableStmt, so copy it.
+	 * (This is overkill, but easy.)
+	 */
+	stmt = (AlterTableStmt *) copyObject(stmt);
+
+	/*
+	 * Acquire exclusive lock on the target relation, which will be held
+	 * until end of transaction.  This ensures any decisions we make here
+	 * based on the state of the relation will still be good at execution.
+	 * We must get exclusive lock now because execution will; taking a lower
+	 * grade lock now and trying to upgrade later risks deadlock.
+	 */
+	rel = relation_openrv(stmt->relation, AccessExclusiveLock);
+
+	/* Set up pstate */
+	pstate = make_parsestate(NULL);
+	pstate->p_sourcetext = queryString;
+
+	cxt.stmtType = "ALTER TABLE";
+	cxt.relation = stmt->relation;
+	cxt.rel = rel;
+	cxt.inhRelations = NIL;
+	cxt.isalter = true;
+	cxt.hasoids = false;		/* need not be right */
+	cxt.columns = NIL;
+	cxt.ckconstraints = NIL;
+	cxt.fkconstraints = NIL;
+	cxt.ixconstraints = NIL;
+	cxt.blist = NIL;
+	cxt.alist = NIL;
+	cxt.pkey = NULL;
+
+	/*
+	 * The only subtypes that currently require parse transformation handling
+	 * are ADD COLUMN and ADD CONSTRAINT.  These largely re-use code from
+	 * CREATE TABLE.
+	 */
+	foreach(lcmd, stmt->cmds)
+	{
+		AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd);
+
+		switch (cmd->subtype)
+		{
+			case AT_AddColumn:
+				{
+					ColumnDef  *def = (ColumnDef *) cmd->def;
+
+					Assert(IsA(cmd->def, ColumnDef));
+					transformColumnDefinition(pstate, &cxt,
+											  (ColumnDef *) cmd->def);
+
+					/*
+					 * If the column has a non-null default, we can't skip
+					 * validation of foreign keys.
+					 */
+					if (((ColumnDef *) cmd->def)->raw_default != NULL)
+						skipValidation = false;
+
+					newcmds = lappend(newcmds, cmd);
+
+					/*
+					 * Convert an ADD COLUMN ... NOT NULL constraint to a
+					 * separate command
+					 */
+					if (def->is_not_null)
+					{
+						/* Remove NOT NULL from AddColumn */
+						def->is_not_null = false;
+
+						/* Add as a separate AlterTableCmd */
+						newcmd = makeNode(AlterTableCmd);
+						newcmd->subtype = AT_SetNotNull;
+						newcmd->name = pstrdup(def->colname);
+						newcmds = lappend(newcmds, newcmd);
+					}
+
+					/*
+					 * All constraints are processed in other ways. Remove the
+					 * original list
+					 */
+					def->constraints = NIL;
+
+					break;
+				}
+			case AT_AddConstraint:
+
+				/*
+				 * The original AddConstraint cmd node doesn't go to newcmds
+				 */
+
+				if (IsA(cmd->def, Constraint))
+					transformTableConstraint(pstate, &cxt,
+											 (Constraint *) cmd->def);
+				else if (IsA(cmd->def, FkConstraint))
+				{
+					cxt.fkconstraints = lappend(cxt.fkconstraints, cmd->def);
+					skipValidation = false;
+				}
+				else
+					elog(ERROR, "unrecognized node type: %d",
+						 (int) nodeTag(cmd->def));
+				break;
+
+			case AT_ProcessedConstraint:
+
+				/*
+				 * Already-transformed ADD CONSTRAINT, so just make it look
+				 * like the standard case.
+				 */
+				cmd->subtype = AT_AddConstraint;
+				newcmds = lappend(newcmds, cmd);
+				break;
+
+			default:
+				newcmds = lappend(newcmds, cmd);
+				break;
+		}
+	}
+
+	/*
+	 * transformIndexConstraints wants cxt.alist to contain only index
+	 * statements, so transfer anything we already have into save_alist.
+	 * immediately.
+	 */
+	save_alist = cxt.alist;
+	cxt.alist = NIL;
+
+	/* Postprocess index and FK constraints */
+	transformIndexConstraints(pstate, &cxt);
+
+	transformFKConstraints(pstate, &cxt, skipValidation, true);
+
+	/*
+	 * Push any index-creation commands into the ALTER, so that they can be
+	 * scheduled nicely by tablecmds.c.  Note that tablecmds.c assumes that
+	 * the IndexStmt attached to an AT_AddIndex subcommand has already been
+	 * through transformIndexStmt.
+	 */
+	foreach(l, cxt.alist)
+	{
+		Node	   *idxstmt = (Node *) lfirst(l);
+
+		Assert(IsA(idxstmt, IndexStmt));
+		newcmd = makeNode(AlterTableCmd);
+		newcmd->subtype = AT_AddIndex;
+		newcmd->def = (Node *) transformIndexStmt((IndexStmt *) idxstmt,
+												  queryString);
+		newcmds = lappend(newcmds, newcmd);
+	}
+	cxt.alist = NIL;
+
+	/* Append any CHECK or FK constraints to the commands list */
+	foreach(l, cxt.ckconstraints)
+	{
+		newcmd = makeNode(AlterTableCmd);
+		newcmd->subtype = AT_AddConstraint;
+		newcmd->def = (Node *) lfirst(l);
+		newcmds = lappend(newcmds, newcmd);
+	}
+	foreach(l, cxt.fkconstraints)
+	{
+		newcmd = makeNode(AlterTableCmd);
+		newcmd->subtype = AT_AddConstraint;
+		newcmd->def = (Node *) lfirst(l);
+		newcmds = lappend(newcmds, newcmd);
+	}
+
+	/* Close rel but keep lock */
+	relation_close(rel, NoLock);
+
+	/*
+	 * Output results.
+	 */
+	stmt->cmds = newcmds;
+
+	result = lappend(cxt.blist, stmt);
+	result = list_concat(result, cxt.alist);
+	result = list_concat(result, save_alist);
+
+	return result;
+}
+
+
+/*
+ * Preprocess a list of column constraint clauses
+ * to attach constraint attributes to their primary constraint nodes
+ * and detect inconsistent/misplaced constraint attributes.
+ *
+ * NOTE: currently, attributes are only supported for FOREIGN KEY primary
+ * constraints, but someday they ought to be supported for other constraints.
+ */
+static void
+transformConstraintAttrs(List *constraintList)
+{
+	Node	   *lastprimarynode = NULL;
+	bool		saw_deferrability = false;
+	bool		saw_initially = false;
+	ListCell   *clist;
+
+	foreach(clist, constraintList)
+	{
+		Node	   *node = lfirst(clist);
+
+		if (!IsA(node, Constraint))
+		{
+			lastprimarynode = node;
+			/* reset flags for new primary node */
+			saw_deferrability = false;
+			saw_initially = false;
+		}
+		else
+		{
+			Constraint *con = (Constraint *) node;
+
+			switch (con->contype)
+			{
+				case CONSTR_ATTR_DEFERRABLE:
+					if (lastprimarynode == NULL ||
+						!IsA(lastprimarynode, FkConstraint))
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("misplaced DEFERRABLE clause")));
+					if (saw_deferrability)
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("multiple DEFERRABLE/NOT DEFERRABLE clauses not allowed")));
+					saw_deferrability = true;
+					((FkConstraint *) lastprimarynode)->deferrable = true;
+					break;
+				case CONSTR_ATTR_NOT_DEFERRABLE:
+					if (lastprimarynode == NULL ||
+						!IsA(lastprimarynode, FkConstraint))
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("misplaced NOT DEFERRABLE clause")));
+					if (saw_deferrability)
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("multiple DEFERRABLE/NOT DEFERRABLE clauses not allowed")));
+					saw_deferrability = true;
+					((FkConstraint *) lastprimarynode)->deferrable = false;
+					if (saw_initially &&
+						((FkConstraint *) lastprimarynode)->initdeferred)
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("constraint declared INITIALLY DEFERRED must be DEFERRABLE")));
+					break;
+				case CONSTR_ATTR_DEFERRED:
+					if (lastprimarynode == NULL ||
+						!IsA(lastprimarynode, FkConstraint))
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("misplaced INITIALLY DEFERRED clause")));
+					if (saw_initially)
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("multiple INITIALLY IMMEDIATE/DEFERRED clauses not allowed")));
+					saw_initially = true;
+					((FkConstraint *) lastprimarynode)->initdeferred = true;
+
+					/*
+					 * If only INITIALLY DEFERRED appears, assume DEFERRABLE
+					 */
+					if (!saw_deferrability)
+						((FkConstraint *) lastprimarynode)->deferrable = true;
+					else if (!((FkConstraint *) lastprimarynode)->deferrable)
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("constraint declared INITIALLY DEFERRED must be DEFERRABLE")));
+					break;
+				case CONSTR_ATTR_IMMEDIATE:
+					if (lastprimarynode == NULL ||
+						!IsA(lastprimarynode, FkConstraint))
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+							errmsg("misplaced INITIALLY IMMEDIATE clause")));
+					if (saw_initially)
+						ereport(ERROR,
+								(errcode(ERRCODE_SYNTAX_ERROR),
+								 errmsg("multiple INITIALLY IMMEDIATE/DEFERRED clauses not allowed")));
+					saw_initially = true;
+					((FkConstraint *) lastprimarynode)->initdeferred = false;
+					break;
+				default:
+					/* Otherwise it's not an attribute */
+					lastprimarynode = node;
+					/* reset flags for new primary node */
+					saw_deferrability = false;
+					saw_initially = false;
+					break;
+			}
+		}
+	}
+}
+
+/*
+ * Special handling of type definition for a column
+ */
+static void
+transformColumnType(ParseState *pstate, ColumnDef *column)
+{
+	/*
+	 * All we really need to do here is verify that the type is valid.
+	 */
+	Type		ctype = typenameType(pstate, column->typename);
+
+	ReleaseSysCache(ctype);
+}
+
+
+/*
+ * transformCreateSchemaStmt -
+ *	  analyzes the CREATE SCHEMA statement
+ *
+ * Split the schema element list into individual commands and place
+ * them in the result list in an order such that there are no forward
+ * references (e.g. GRANT to a table created later in the list). Note
+ * that the logic we use for determining forward references is
+ * presently quite incomplete.
+ *
+ * SQL92 also allows constraints to make forward references, so thumb through
+ * the table columns and move forward references to a posterior alter-table
+ * command.
+ *
+ * The result is a list of parse nodes that still need to be analyzed ---
+ * but we can't analyze the later commands until we've executed the earlier
+ * ones, because of possible inter-object references.
+ *
+ * Note: this breaks the rules a little bit by modifying schema-name fields
+ * within passed-in structs.  However, the transformation would be the same
+ * if done over, so it should be all right to scribble on the input to this
+ * extent.
+ */
+List *
+transformCreateSchemaStmt(CreateSchemaStmt *stmt)
+{
+	CreateSchemaStmtContext cxt;
+	List	   *result;
+	ListCell   *elements;
+
+	cxt.stmtType = "CREATE SCHEMA";
+	cxt.schemaname = stmt->schemaname;
+	cxt.authid = stmt->authid;
+	cxt.sequences = NIL;
+	cxt.tables = NIL;
+	cxt.views = NIL;
+	cxt.indexes = NIL;
+	cxt.triggers = NIL;
+	cxt.grants = NIL;
+
+	/*
+	 * Run through each schema element in the schema element list. Separate
+	 * statements by type, and do preliminary analysis.
+	 */
+	foreach(elements, stmt->schemaElts)
+	{
+		Node	   *element = lfirst(elements);
+
+		switch (nodeTag(element))
+		{
+			case T_CreateSeqStmt:
+				{
+					CreateSeqStmt *elp = (CreateSeqStmt *) element;
+
+					setSchemaName(cxt.schemaname, &elp->sequence->schemaname);
+					cxt.sequences = lappend(cxt.sequences, element);
+				}
+				break;
+
+			case T_CreateStmt:
+				{
+					CreateStmt *elp = (CreateStmt *) element;
+
+					setSchemaName(cxt.schemaname, &elp->relation->schemaname);
+
+					/*
+					 * XXX todo: deal with constraints
+					 */
+					cxt.tables = lappend(cxt.tables, element);
+				}
+				break;
+
+			case T_ViewStmt:
+				{
+					ViewStmt   *elp = (ViewStmt *) element;
+
+					setSchemaName(cxt.schemaname, &elp->view->schemaname);
+
+					/*
+					 * XXX todo: deal with references between views
+					 */
+					cxt.views = lappend(cxt.views, element);
+				}
+				break;
+
+			case T_IndexStmt:
+				{
+					IndexStmt  *elp = (IndexStmt *) element;
+
+					setSchemaName(cxt.schemaname, &elp->relation->schemaname);
+					cxt.indexes = lappend(cxt.indexes, element);
+				}
+				break;
+
+			case T_CreateTrigStmt:
+				{
+					CreateTrigStmt *elp = (CreateTrigStmt *) element;
+
+					setSchemaName(cxt.schemaname, &elp->relation->schemaname);
+					cxt.triggers = lappend(cxt.triggers, element);
+				}
+				break;
+
+			case T_GrantStmt:
+				cxt.grants = lappend(cxt.grants, element);
+				break;
+
+			default:
+				elog(ERROR, "unrecognized node type: %d",
+					 (int) nodeTag(element));
+		}
+	}
+
+	result = NIL;
+	result = list_concat(result, cxt.sequences);
+	result = list_concat(result, cxt.tables);
+	result = list_concat(result, cxt.views);
+	result = list_concat(result, cxt.indexes);
+	result = list_concat(result, cxt.triggers);
+	result = list_concat(result, cxt.grants);
+
+	return result;
+}
+
+/*
+ * setSchemaName
+ *		Set or check schema name in an element of a CREATE SCHEMA command
+ */
+static void
+setSchemaName(char *context_schema, char **stmt_schema_name)
+{
+	if (*stmt_schema_name == NULL)
+		*stmt_schema_name = context_schema;
+	else if (strcmp(context_schema, *stmt_schema_name) != 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_SCHEMA_DEFINITION),
+				 errmsg("CREATE specifies a schema (%s) "
+						"different from the one being created (%s)",
+						*stmt_schema_name, context_schema)));
+}