35a36,47
> 
> #include "parser/parse_expr.h"
> #include "parser/parse_clause.h"
> #include "parser/parse_relation.h"
> #include "nodes/makefuncs.h"
> #include "optimizer/planmain.h"
> #include "optimizer/clauses.h"
> #include "rewrite/rewriteSupport.h"
> #include "commands/view.h"
> #include "utils/temprel.h"
> #include "executor/spi_priv.h"
> 
1069a1082,1085
> 	char rulequery[41+NAMEDATALEN]; 
> 	void *qplan;
> 	char nulls[1]="";
> 
1072a1089,1108
> #ifndef NO_SECURITY
> 	if (!pg_ownercheck(UserName, relationName, RELNAME))
> 		elog(ERROR, "ALTER TABLE: permission denied");
> #endif
> 
> 	/* check to see if the table to be constrained is a view. */
> 	sprintf(rulequery, "select * from pg_views where viewname='%s'", relationName);
> 	if (SPI_connect()!=SPI_OK_CONNECT)
> 		elog(ERROR, "ALTER TABLE: Unable to determine if %s is a view - SPI_connect failure..", relationName);
>         qplan=SPI_prepare(rulequery, 0, NULL);
> 	if (!qplan)
> 		elog(ERROR, "ALTER TABLE: Unable to determine if %s is a view - SPI_prepare failure.", relationName);
> 	qplan=SPI_saveplan(qplan);
> 	if (SPI_execp(qplan, NULL, nulls, 1)!=SPI_OK_SELECT) 
> 		elog(ERROR, "ALTER TABLE: Unable to determine if %s is a view - SPI_execp failure.", relationName);
>         if (SPI_processed != 0)
>                 elog(ERROR, "ALTER TABLE: Cannot add constraints to views.");
>         if (SPI_finish() != SPI_OK_FINISH)
>                 elog(NOTICE, "SPI_finish() failed in ALTER TABLE");
> 		
1076c1112,1233
< 			elog(ERROR, "ALTER TABLE / ADD CONSTRAINT is not implemented");
---
> 			{
> 				Constraint *constr=(Constraint *)newConstraint;
> 				switch (constr->contype) {
> 					case CONSTR_CHECK:
> 					{
> 						ParseState *pstate;
> 						bool successful=TRUE;
> 						HeapScanDesc scan;
> 					        ExprContext *econtext;
> 					        TupleTableSlot *slot = makeNode(TupleTableSlot);
> 						HeapTuple tuple;
> 					        RangeTblEntry *rte = makeNode(RangeTblEntry);
> 					        List       *rtlist;
> 					        List       *qual;
> 						List       *constlist;
> 						Relation	rel;
> 						Node *expr;
> 						char *name;
> 						if (constr->name)
> 							name=constr->name;
> 						else
> 							name="<unnamed>";
> 
> 						rel = heap_openr(relationName, AccessExclusiveLock);
> 
> 						/*
> 						 * Scan all of the rows, looking for a false match
> 						 */
> 						scan = heap_beginscan(rel, false, SnapshotNow, 0, NULL);
> 						AssertState(scan != NULL);
> 
> 						/* 
> 						 *We need to make a parse state and range table to allow us
> 						 * to transformExpr and fix_opids to get a version of the
> 					 	 * expression we can pass to ExecQual
> 						 */
> 						pstate = make_parsestate(NULL);
> 					        makeRangeTable(pstate, NULL);
> 					        addRangeTableEntry(pstate, relationName, 
> 							makeAttr(relationName, NULL), false, true,true);
> 						constlist=lcons(constr, NIL);
> 
> 						/* Convert the A_EXPR in raw_expr into an EXPR */
> 				                expr = transformExpr(pstate, constr->raw_expr, EXPR_COLUMN_FIRST);
> 
> 				                /*
> 				                 * Make sure it yields a boolean result.
> 				                 */
> 				                if (exprType(expr) != BOOLOID)
> 				                        elog(ERROR, "CHECK '%s' does not yield boolean result",
>                                 			 name);
> 
> 				                /*
> 				                 * Make sure no outside relations are referred to.
> 				                 */
> 				                if (length(pstate->p_rtable) != 1)
>                 				        elog(ERROR, "Only relation '%s' can be referenced in CHECK",
> 		                        	         relationName);
> 
>         				        /*
> 				                 * Might as well try to reduce any constant expressions.
> 				                 */
> 				                expr = eval_const_expressions(expr);
> 
> 						/* And fix the opids */
> 						fix_opids(expr);
> 
> 						qual = lcons(expr, NIL);
>        						rte->relname = relationName;
> 					        rte->ref = makeNode(Attr);
> 					        rte->ref->relname = rte->relname;
> 					        rte->relid = RelationGetRelid(rel);
> 					        rtlist = lcons(rte, NIL);
> 
> 						/* 
> 						 * Scan through the rows now, making the necessary things for
> 						 * ExecQual, and then call it to evaluate the expression.
> 						 */
> 						while (HeapTupleIsValid(tuple = heap_getnext(scan, 0)))
> 						{
> 						        slot->val = tuple;
> 						        slot->ttc_shouldFree = false;
> 						        slot->ttc_descIsNew = true;
> 						        slot->ttc_tupleDescriptor = rel->rd_att;
> 						        slot->ttc_buffer = InvalidBuffer;
> 						        slot->ttc_whichplan = -1;
> 
> 							econtext = MakeExprContext(slot, CurrentMemoryContext);
> 						        econtext->ecxt_range_table = rtlist;            /* range table */
> 						        if (!ExecQual(qual, econtext, true)) {
> 								successful=false;
> 								break;
> 						        }
> 							FreeExprContext(econtext);
> 						}
> 
> 					        pfree(slot);
> 					        pfree(rtlist);
> 					        pfree(rte);
> 
> 						heap_endscan(scan);
> 						heap_close(rel, NoLock);		
> 
> 						if (!successful) 
> 						{
> 							elog(ERROR, "AlterTableAddConstraint: rejected due to CHECK constraint %s", name);
> 						}
> 						/* 
> 						 * Call AddRelationRawConstraints to do the real adding -- It duplicates some
> 						 * of the above, but does not check the validity of the constraint against
> 						 * tuples already in the table.
> 						 */
> 						AddRelationRawConstraints(rel, NIL, constlist);
> 					        pfree(constlist);
> 
> 						break;
> 					}
> 					default:
> 						elog(ERROR, "ALTER TABLE / ADD CONSTRAINT is not implemented for that constraint type.");
> 				}
> 			}
> 			break;
1086a1244,1263
> 				if (get_temp_rel_by_username(fkconstraint->pktable_name)!=NULL &&
> 				    get_temp_rel_by_username(relationName)==NULL) {
> 					elog(ERROR, "ALTER TABLE / ADD CONSTRAINT: Unable to reference temporary table from permanent table constraint.");
> 				}
> 
> 				/* check to see if the referenced table is a view. */
> 				sprintf(rulequery, "select * from pg_views where viewname='%s'", fkconstraint->pktable_name);
> 				if (SPI_connect()!=SPI_OK_CONNECT)
> 					elog(ERROR, "ALTER TABLE: Unable to determine if %s is a view.", relationName);
> 			        qplan=SPI_prepare(rulequery, 0, NULL);
> 				if (!qplan)
> 					elog(ERROR, "ALTER TABLE: Unable to determine if %s is a view.", relationName);
> 				qplan=SPI_saveplan(qplan);
> 				if (SPI_execp(qplan, NULL, nulls, 1)!=SPI_OK_SELECT) 
> 					elog(ERROR, "ALTER TABLE: Unable to determine if %s is a view.", relationName);
> 			        if (SPI_processed != 0)
> 			                elog(ERROR, "ALTER TABLE: Cannot add constraints to views.");
> 			        if (SPI_finish() != SPI_OK_FINISH)
> 			                elog(NOTICE, "SPI_finish() failed in RI_FKey_check()");
> 
1104c1281,1284
< 				trig.tgname = "<unknown>";
---
> 				if (fkconstraint->constr_name)
> 					trig.tgname = fkconstraint->constr_name;
> 				else
> 					trig.tgname = "<unknown>";
1116c1296,1299
< 				trig.tgargs[0] = "<unnamed>";
---
> 				if (fkconstraint->constr_name)
> 					trig.tgargs[0] = fkconstraint->constr_name;
> 				else
> 					trig.tgargs[0] = "<unknown>";
1439a1623
>