Enable CHECK constraints to be declared NOT VALID

This means that they can initially be added to a large existing table
without checking its initial contents, but new tuples must comply to
them; a separate pass invoked by ALTER TABLE / VALIDATE can verify
existing data and ensure it complies with the constraint, at which point
it is marked validated and becomes a normal part of the table ecosystem.

An non-validated CHECK constraint is ignored in the planner for
constraint_exclusion purposes; when validated, cached plans are
recomputed so that partitioning starts working right away.

This patch also enables domains to have unvalidated CHECK constraints
attached to them as well by way of ALTER DOMAIN / ADD CONSTRAINT / NOT
VALID, which can later be validated with ALTER DOMAIN / VALIDATE
CONSTRAINT.

Thanks to Thom Brown, Dean Rasheed and Jaime Casanova for the various
reviews, and Robert Hass for documentation wording improvement
suggestions.

This patch was sponsored by Enova Financial.

doc/src/sgml/catalogs.sgml

@@ -1899,7 +1899,7 @@
       <entry><type>bool</type></entry>
       <entry></entry>
       <entry>Has the constraint been validated?
-       Currently, can only be false for foreign keys</entry>
+       Currently, can only be false for foreign keys and CHECK constraints</entry>
      </row>
 
      <row>

doc/src/sgml/ref/alter_domain.sgml

@@ -28,9 +28,11 @@ ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
 ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
     { SET | DROP } NOT NULL
 ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
-    ADD <replaceable class="PARAMETER">domain_constraint</replaceable>
+    ADD <replaceable class="PARAMETER">domain_constraint</replaceable> [ NOT VALID ]
 ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
     DROP CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable> [ RESTRICT | CASCADE ]
+ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
+    VALIDATE CONSTRAINT <replaceable class="PARAMETER">constraint_name</replaceable>
 ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
     OWNER TO <replaceable class="PARAMETER">new_owner</replaceable>
 ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
@@ -70,13 +72,19 @@ ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
    </varlistentry>
 
    <varlistentry>
-    <term>ADD <replaceable class="PARAMETER">domain_constraint</replaceable></term>
+    <term>ADD <replaceable class="PARAMETER">domain_constraint</replaceable> [ NOT VALID ]</term>
     <listitem>
      <para>
       This form adds a new constraint to a domain using the same syntax as
       <xref linkend="SQL-CREATEDOMAIN">.
-      This will only succeed if all columns using the domain satisfy the
-      new constraint.
+      When a new constraint is added to a domain, all columns using that
+      domain will be checked against the newly added constraint.  These
+      checks can be suppressed by adding the new constraint using the
+      <literal>NOT VALID</literal> option; the constraint can later be made
+      valid using <command>ALTER DOMAIN ... VALIDATE CONSTRAINT</command>.
+      Newly inserted or updated rows are always checked against all
+      constraints, even those marked <literal>NOT VALID</literal>.
+      <literal>NOT VALID</> is only accepted for <literal>CHECK</> constraints.
      </para>
     </listitem>
    </varlistentry>
@@ -90,6 +98,17 @@ ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term>VALIDATE CONSTRAINT</term>
+    <listitem>
+     <para>
+      This form validates a constraint previously added as
+      <literal>NOT VALID</>, that is, verify that all data in columns using the
+      domain satisfy the specified constraint.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term>OWNER</term>
     <listitem>
@@ -155,6 +174,16 @@ ALTER DOMAIN <replaceable class="PARAMETER">name</replaceable>
       </listitem>
      </varlistentry>
 
+     <varlistentry>
+      <term><replaceable class="PARAMETER">NOT VALID</replaceable></term>
+      <listitem>
+       <para>
+        Do not verify existing column data for constraint validity.
+       </para>
+      </listitem>
+     </varlistentry>
+
+
      <varlistentry>
       <term><literal>CASCADE</literal></term>
       <listitem>
@@ -250,9 +279,11 @@ ALTER DOMAIN zipcode SET SCHEMA customers;
 
   <para>
    <command>ALTER DOMAIN</command> conforms to the <acronym>SQL</acronym>
-   standard,
-   except for the <literal>OWNER</> and <literal>SET SCHEMA</> variants,
-   which are <productname>PostgreSQL</productname> extensions.
+   standard, except for the <literal>OWNER</>, <literal>SET SCHEMA</> and
+   <literal>VALIDATE CONSTRAINT</> variants, which are
+   <productname>PostgreSQL</productname> extensions.  The <literal>NOT VALID</>
+   clause of the <literal>ADD CONSTRAINT</> variant is also a
+   <productname>PostgreSQL</productname> extension.
   </para>
  </refsect1>
 

doc/src/sgml/ref/alter_table.sgml

@@ -240,12 +240,14 @@ ALTER TABLE <replaceable class="PARAMETER">name</replaceable>
       This form adds a new constraint to a table using the same syntax as
       <xref linkend="SQL-CREATETABLE">, plus the option <literal>NOT
       VALID</literal>, which is currently only allowed for foreign key
-      constraints.
+      and CHECK constraints.
       If the constraint is marked <literal>NOT VALID</literal>, the
       potentially-lengthy initial check to verify that all rows in the table
       satisfy the constraint is skipped.  The constraint will still be
       enforced against subsequent inserts or updates (that is, they'll fail
-      unless there is a matching row in the referenced table).  But the
+      unless there is a matching row in the referenced table, in the case
+      of foreign keys; and they'll fail unless the new row matches the
+      specified check constraints).  But the
       database will not assume that the constraint holds for all rows in
       the table, until it is validated by using the <literal>VALIDATE
       CONSTRAINT</literal> option.
@@ -308,10 +310,10 @@ ALTER TABLE <replaceable class="PARAMETER">name</replaceable>
     <term><literal>VALIDATE CONSTRAINT</literal></term>
     <listitem>
      <para>
-      This form validates a foreign key constraint that was previously created
+      This form validates a foreign key or check constraint that was previously created
       as <literal>NOT VALID</literal>, by scanning the table to ensure there
-      are no unmatched rows.  Nothing happens if the constraint is
-      already marked valid.
+      are no rows for which the constraint is not satisfied.
+      Nothing happens if the constraint is already marked valid.
       The value of separating validation from initial creation of the
       constraint is that validation requires a lesser lock on the table
       than constraint creation does.

src/backend/access/common/tupdesc.c

@@ -200,6 +200,7 @@ CreateTupleDescCopyConstr(TupleDesc tupdesc)
 					cpy->check[i].ccname = pstrdup(constr->check[i].ccname);
 				if (constr->check[i].ccbin)
 					cpy->check[i].ccbin = pstrdup(constr->check[i].ccbin);
+				cpy->check[i].ccvalid = constr->check[i].ccvalid;
 			}
 		}
 

src/backend/catalog/heap.c

@@ -98,7 +98,7 @@ static Oid AddNewRelationType(const char *typeName,
 				   Oid new_array_type);
 static void RelationRemoveInheritance(Oid relid);
 static void StoreRelCheck(Relation rel, char *ccname, Node *expr,
-			  bool is_local, int inhcount);
+			  bool is_validated, bool is_local, int inhcount);
 static void StoreConstraints(Relation rel, List *cooked_constraints);
 static bool MergeWithExistingConstraint(Relation rel, char *ccname, Node *expr,
 							bool allow_merge, bool is_local);
@@ -1846,7 +1846,7 @@ StoreAttrDefault(Relation rel, AttrNumber attnum, Node *expr)
  */
 static void
 StoreRelCheck(Relation rel, char *ccname, Node *expr,
-			  bool is_local, int inhcount)
+			  bool is_validated, bool is_local, int inhcount)
 {
 	char	   *ccbin;
 	char	   *ccsrc;
@@ -1907,7 +1907,7 @@ StoreRelCheck(Relation rel, char *ccname, Node *expr,
 						  CONSTRAINT_CHECK,		/* Constraint Type */
 						  false,	/* Is Deferrable */
 						  false,	/* Is Deferred */
-						  true, /* Is Validated */
+						  is_validated,
 						  RelationGetRelid(rel),		/* relation */
 						  attNos,		/* attrs in the constraint */
 						  keycount,		/* # attrs in the constraint */
@@ -1967,7 +1967,7 @@ StoreConstraints(Relation rel, List *cooked_constraints)
 				StoreAttrDefault(rel, con->attnum, con->expr);
 				break;
 			case CONSTR_CHECK:
-				StoreRelCheck(rel, con->name, con->expr,
+				StoreRelCheck(rel, con->name, con->expr, !con->skip_validation,
 							  con->is_local, con->inhcount);
 				numchecks++;
 				break;
@@ -2081,6 +2081,7 @@ AddRelationNewConstraints(Relation rel,
 		cooked->name = NULL;
 		cooked->attnum = colDef->attnum;
 		cooked->expr = expr;
+		cooked->skip_validation = false;
 		cooked->is_local = is_local;
 		cooked->inhcount = is_local ? 0 : 1;
 		cookedConstraints = lappend(cookedConstraints, cooked);
@@ -2194,7 +2195,8 @@ AddRelationNewConstraints(Relation rel,
 		/*
 		 * OK, store it.
 		 */
-		StoreRelCheck(rel, ccname, expr, is_local, is_local ? 0 : 1);
+		StoreRelCheck(rel, ccname, expr, !cdef->skip_validation, is_local,
+					  is_local ? 0 : 1);
 
 		numchecks++;
 
@@ -2203,6 +2205,7 @@ AddRelationNewConstraints(Relation rel,
 		cooked->name = ccname;
 		cooked->attnum = 0;
 		cooked->expr = expr;
+		cooked->skip_validation = cdef->skip_validation;
 		cooked->is_local = is_local;
 		cooked->inhcount = is_local ? 0 : 1;
 		cookedConstraints = lappend(cookedConstraints, cooked);

src/backend/commands/typecmds.c

@@ -86,6 +86,7 @@ static Oid	findTypeSendFunction(List *procname, Oid typeOid);
 static Oid	findTypeTypmodinFunction(List *procname);
 static Oid	findTypeTypmodoutFunction(List *procname);
 static Oid	findTypeAnalyzeFunction(List *procname, Oid typeOid);
+static void	validateDomainConstraint(Oid domainoid, char *ccbin);
 static List *get_rels_with_domain(Oid domainOid, LOCKMODE lockmode);
 static void checkDomainOwner(HeapTuple tup);
 static void checkEnumOwner(HeapTuple tup);
@@ -1941,14 +1942,8 @@ AlterDomainAddConstraint(List *names, Node *newConstraint)
 	Relation	typrel;
 	HeapTuple	tup;
 	Form_pg_type typTup;
-	List	   *rels;
-	ListCell   *rt;
-	EState	   *estate;
-	ExprContext *econtext;
-	char	   *ccbin;
-	Expr	   *expr;
-	ExprState  *exprstate;
 	Constraint *constr;
+	char	   *ccbin;
 
 	/* Make a TypeName so we can use standard type lookup machinery */
 	typename = makeTypeNameFromNameList(names);
@@ -2027,10 +2022,129 @@ AlterDomainAddConstraint(List *names, Node *newConstraint)
 								constr, NameStr(typTup->typname));
 
 	/*
-	 * Test all values stored in the attributes based on the domain the
-	 * constraint is being added to.
+	 * If requested to validate the constraint, test all values stored in the
+	 * attributes based on the domain the constraint is being added to.
 	 */
-	expr = (Expr *) stringToNode(ccbin);
+	if (!constr->skip_validation)
+		validateDomainConstraint(domainoid, ccbin);
+
+	/* Clean up */
+	heap_close(typrel, RowExclusiveLock);
+}
+
+/*
+ * AlterDomainValidateConstraint
+ *
+ * Implements the ALTER DOMAIN .. VALIDATE CONSTRAINT statement.
+ */
+void
+AlterDomainValidateConstraint(List *names, char *constrName)
+{
+	TypeName   *typename;
+	Oid			domainoid;
+	Relation	typrel;
+	Relation	conrel;
+	HeapTuple	tup;
+	Form_pg_type typTup;
+	Form_pg_constraint con;
+	Form_pg_constraint copy_con;
+	char	   *conbin;
+	SysScanDesc	scan;
+	Datum		val;
+	bool		found = false;
+	bool		isnull;
+	HeapTuple	tuple;
+	HeapTuple	copyTuple;
+	ScanKeyData	key;
+
+	/* Make a TypeName so we can use standard type lookup machinery */
+	typename = makeTypeNameFromNameList(names);
+	domainoid = typenameTypeId(NULL, typename);
+
+	/* Look up the domain in the type table */
+	typrel = heap_open(TypeRelationId, AccessShareLock);
+
+	tup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(domainoid));
+	if (!HeapTupleIsValid(tup))
+		elog(ERROR, "cache lookup failed for type %u", domainoid);
+	typTup = (Form_pg_type) GETSTRUCT(tup);
+
+	/* Check it's a domain and check user has permission for ALTER DOMAIN */
+	checkDomainOwner(tup);
+
+	/*
+	 * Find and check the target constraint
+	 */
+	conrel = heap_open(ConstraintRelationId, RowExclusiveLock);
+	ScanKeyInit(&key,
+				Anum_pg_constraint_contypid,
+				BTEqualStrategyNumber, F_OIDEQ,
+				ObjectIdGetDatum(domainoid));
+	scan = systable_beginscan(conrel, ConstraintTypidIndexId,
+							  true, SnapshotNow, 1, &key);
+
+	while (HeapTupleIsValid(tuple = systable_getnext(scan)))
+	{
+		con = (Form_pg_constraint) GETSTRUCT(tuple);
+		if (strcmp(NameStr(con->conname), constrName) == 0)
+		{
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
+	{
+		con = NULL;		/* keep compiler quiet */
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("constraint \"%s\" of domain \"%s\" does not exist",
+						constrName, NameStr(con->conname))));
+	}
+
+	if (con->contype != CONSTRAINT_CHECK)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("constraint \"%s\" of domain \"%s\" is not a check constraint",
+						constrName, NameStr(con->conname))));
+
+	val = SysCacheGetAttr(CONSTROID, tuple,
+						  Anum_pg_constraint_conbin,
+						  &isnull);
+	if (isnull)
+		elog(ERROR, "null conbin for constraint %u",
+			 HeapTupleGetOid(tuple));
+	conbin = TextDatumGetCString(val);
+
+	validateDomainConstraint(domainoid, conbin);
+
+	/*
+	 * Now update the catalog, while we have the door open.
+	 */
+	copyTuple = heap_copytuple(tuple);
+	copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
+	copy_con->convalidated = true;
+	simple_heap_update(conrel, &copyTuple->t_self, copyTuple);
+	CatalogUpdateIndexes(conrel, copyTuple);
+	heap_freetuple(copyTuple);
+
+	systable_endscan(scan);
+
+	heap_close(typrel, AccessShareLock);
+	heap_close(conrel, RowExclusiveLock);
+
+	ReleaseSysCache(tup);
+}
+
+static void
+validateDomainConstraint(Oid domainoid, char *ccbin)
+{
+	Expr	   *expr = (Expr *) stringToNode(ccbin);
+	List	   *rels;
+	ListCell   *rt;
+	EState	   *estate;
+	ExprContext *econtext;
+	ExprState  *exprstate;
 
 	/* Need an EState to run ExecEvalExpr */
 	estate = CreateExecutorState();
@@ -2092,11 +2206,7 @@ AlterDomainAddConstraint(List *names, Node *newConstraint)
 	}
 
 	FreeExecutorState(estate);
-
-	/* Clean up */
-	heap_close(typrel, RowExclusiveLock);
 }
-
 /*
  * get_rels_with_domain
  *
@@ -2416,7 +2526,7 @@ domainAddConstraint(Oid domainOid, Oid domainNamespace, Oid baseTypeOid,
 						  CONSTRAINT_CHECK,		/* Constraint Type */
 						  false,	/* Is Deferrable */
 						  false,	/* Is Deferred */
-						  true, /* Is Validated */
+						  !constr->skip_validation, /* Is Validated */
 						  InvalidOid,	/* not a relation constraint */
 						  NULL,
 						  0,

src/backend/optimizer/util/plancat.c

@@ -552,7 +552,7 @@ get_relation_data_width(Oid relid, int32 *attr_widths)
 /*
  * get_relation_constraints
  *
- * Retrieve the CHECK constraint expressions of the given relation.
+ * Retrieve the validated CHECK constraint expressions of the given relation.
  *
  * Returns a List (possibly empty) of constraint expressions.  Each one
  * has been canonicalized, and its Vars are changed to have the varno
@@ -591,6 +591,13 @@ get_relation_constraints(PlannerInfo *root,
 		{
 			Node	   *cexpr;
 
+			/*
+			 * If this constraint hasn't been fully validated yet, we must
+			 * ignore it here.
+			 */
+			if (!constr->check[i].ccvalid)
+				continue;
+
 			cexpr = stringToNode(constr->check[i].ccbin);
 
 			/*
@@ -663,7 +670,7 @@ get_relation_constraints(PlannerInfo *root,
  *
  * Detect whether the relation need not be scanned because it has either
  * self-inconsistent restrictions, or restrictions inconsistent with the
- * relation's CHECK constraints.
+ * relation's validated CHECK constraints.
  *
  * Note: this examines only rel->relid, rel->reloptkind, and
  * rel->baserestrictinfo; therefore it can be called before filling in

src/backend/parser/gram.y

@@ -2759,8 +2759,9 @@ ConstraintElem:
 					n->raw_expr = $3;
 					n->cooked_expr = NULL;
 					processCASbits($5, @5, "CHECK",
-								   NULL, NULL, NULL,
+								   NULL, NULL, &n->skip_validation,
 								   yyscanner);
+					n->initially_valid = !n->skip_validation;
 					$$ = (Node *)n;
 				}
 			| UNIQUE '(' columnList ')' opt_definition OptConsTableSpace
@@ -7559,6 +7560,15 @@ AlterDomainStmt:
 					n->behavior = $7;
 					$$ = (Node *)n;
 				}
+			/* ALTER DOMAIN <domain> VALIDATE CONSTRAINT <name> */
+			| ALTER DOMAIN_P any_name VALIDATE CONSTRAINT name
+				{
+					AlterDomainStmt *n = makeNode(AlterDomainStmt);
+					n->subtype = 'V';
+					n->typeName = $3;
+					n->name = $6;
+					$$ = (Node *)n;
+				}
 			;
 
 opt_as:		AS										{}

src/backend/tcop/utility.c

@@ -820,6 +820,10 @@ standard_ProcessUtility(Node *parsetree,
 												  stmt->name,
 												  stmt->behavior);
 						break;
+					case 'V':	/* VALIDATE CONSTRAINT */
+						AlterDomainValidateConstraint(stmt->typeName,
+													  stmt->name);
+						break;
 					default:	/* oops */
 						elog(ERROR, "unrecognized alter domain type: %d",
 							 (int) stmt->subtype);

src/backend/utils/cache/relcache.c

@@ -3251,6 +3251,7 @@ CheckConstraintFetch(Relation relation)
 			elog(ERROR, "unexpected constraint record found for rel %s",
 				 RelationGetRelationName(relation));
 
+		check[found].ccvalid = conform->convalidated;
 		check[found].ccname = MemoryContextStrdup(CacheMemoryContext,
 												  NameStr(conform->conname));
 

src/include/access/tupdesc.h

@@ -29,6 +29,7 @@ typedef struct constrCheck
 {
 	char	   *ccname;
 	char	   *ccbin;			/* nodeToString representation of expr */
+	bool		ccvalid;
 } ConstrCheck;
 
 /* This structure contains constraints of a tuple */

src/include/catalog/heap.h

@@ -30,6 +30,7 @@ typedef struct CookedConstraint
 	char	   *name;			/* name, or NULL if none */
 	AttrNumber	attnum;			/* which attr (only for DEFAULT) */
 	Node	   *expr;			/* transformed default or check expr */
+	bool		skip_validation;	/* skip validation? (only for CHECK) */
 	bool		is_local;		/* constraint has local (non-inherited) def */
 	int			inhcount;		/* number of times constraint is inherited */
 } CookedConstraint;

src/include/commands/typecmds.h

@@ -31,6 +31,7 @@ extern Oid	AssignTypeArrayOid(void);
 extern void AlterDomainDefault(List *names, Node *defaultRaw);
 extern void AlterDomainNotNull(List *names, bool notNull);
 extern void AlterDomainAddConstraint(List *names, Node *constr);
+extern void AlterDomainValidateConstraint(List *names, char *constrName);
 extern void AlterDomainDropConstraint(List *names, const char *constrName,
 						  DropBehavior behavior);
 

src/include/nodes/parsenodes.h

@@ -1190,6 +1190,7 @@ typedef enum AlterTableType
 	AT_AddConstraint,			/* add constraint */
 	AT_AddConstraintRecurse,	/* internal to commands/tablecmds.c */
 	AT_ValidateConstraint,		/* validate constraint */
+	AT_ValidateConstraintRecurse, /* internal to commands/tablecmds.c */
 	AT_ProcessedConstraint,		/* pre-processed add constraint (local in
 								 * parser/parse_utilcmd.c) */
 	AT_AddIndexConstraint,		/* add constraint using existing index */
@@ -1543,6 +1544,8 @@ typedef struct Constraint
 	char		fk_matchtype;	/* FULL, PARTIAL, UNSPECIFIED */
 	char		fk_upd_action;	/* ON UPDATE action */
 	char		fk_del_action;	/* ON DELETE action */
+
+	/* Fields used for constraints that allow a NOT VALID specification */
 	bool		skip_validation;	/* skip validation of existing rows? */
 	bool		initially_valid;	/* mark the new constraint as valid? */
 } Constraint;

src/test/regress/expected/alter_table.out

@@ -196,14 +196,115 @@ DELETE FROM tmp3 where a=5;
 -- Try (and succeed) and repeat to show it works on already valid constraint
 ALTER TABLE tmp3 validate constraint tmpconstr;
 ALTER TABLE tmp3 validate constraint tmpconstr;
+-- Try a non-verified CHECK constraint
+ALTER TABLE tmp3 ADD CONSTRAINT b_greater_than_ten CHECK (b > 10); -- fail
+ERROR:  check constraint "b_greater_than_ten" is violated by some row
+ALTER TABLE tmp3 ADD CONSTRAINT b_greater_than_ten CHECK (b > 10) NOT VALID; -- succeeds
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_greater_than_ten; -- fails
+ERROR:  check constraint "b_greater_than_ten" is violated by some row
+DELETE FROM tmp3 WHERE NOT b > 10;
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_greater_than_ten; -- succeeds
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_greater_than_ten; -- succeeds
+-- Test inherited NOT VALID CHECK constraints
+select * from tmp3;
+ a | b  
+---+----
+ 1 | 20
+(1 row)
+
+CREATE TABLE tmp6 () INHERITS (tmp3);
+CREATE TABLE tmp7 () INHERITS (tmp3);
+INSERT INTO tmp6 VALUES (6, 30), (7, 16);
+ALTER TABLE tmp3 ADD CONSTRAINT b_le_20 CHECK (b <= 20) NOT VALID;
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_le_20;	-- fails
+ERROR:  check constraint "b_le_20" is violated by some row
+DELETE FROM tmp6 WHERE b > 20;
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_le_20;	-- succeeds
+-- An already validated constraint must not be revalidated
+CREATE FUNCTION boo(int) RETURNS int IMMUTABLE STRICT LANGUAGE plpgsql AS $$ BEGIN RAISE NOTICE 'boo: %', $1; RETURN $1; END; $$;
+INSERT INTO tmp7 VALUES (8, 18);
+ALTER TABLE tmp7 ADD CONSTRAINT identity CHECK (b = boo(b));
+NOTICE:  boo: 18
+ALTER TABLE tmp3 ADD CONSTRAINT IDENTITY check (b = boo(b)) NOT VALID;
+NOTICE:  merging constraint "identity" with inherited definition
+ALTER TABLE tmp3 VALIDATE CONSTRAINT identity;
+NOTICE:  boo: 16
+NOTICE:  boo: 20
 -- Try (and fail) to create constraint from tmp5(a) to tmp4(a) - unique constraint on
 -- tmp4 is a,b
 ALTER TABLE tmp5 add constraint tmpconstr foreign key(a) references tmp4(a) match full;
 ERROR:  there is no unique constraint matching given keys for referenced table "tmp4"
+DROP TABLE tmp7;
+DROP TABLE tmp6;
 DROP TABLE tmp5;
 DROP TABLE tmp4;
 DROP TABLE tmp3;
 DROP TABLE tmp2;
+-- NOT VALID with plan invalidation -- ensure we don't use a constraint for
+-- exclusion until validated
+set constraint_exclusion TO 'partition';
+create table nv_parent (d date); 
+create table nv_child_2010 () inherits (nv_parent);
+create table nv_child_2011 () inherits (nv_parent);
+alter table nv_child_2010 add check (d between '2010-01-01'::date and '2010-12-31'::date) not valid;
+alter table nv_child_2011 add check (d between '2011-01-01'::date and '2011-12-31'::date) not valid;
+explain (costs off) select * from nv_parent where d between '2011-08-01' and '2011-08-31';
+                                   QUERY PLAN                                    
+---------------------------------------------------------------------------------
+ Result
+   ->  Append
+         ->  Seq Scan on nv_parent
+               Filter: ((d >= '08-01-2011'::date) AND (d <= '08-31-2011'::date))
+         ->  Seq Scan on nv_child_2010 nv_parent
+               Filter: ((d >= '08-01-2011'::date) AND (d <= '08-31-2011'::date))
+         ->  Seq Scan on nv_child_2011 nv_parent
+               Filter: ((d >= '08-01-2011'::date) AND (d <= '08-31-2011'::date))
+(8 rows)
+
+create table nv_child_2009 (check (d between '2009-01-01'::date and '2009-12-31'::date)) inherits (nv_parent);
+explain (costs off) select * from nv_parent where d between '2011-08-01'::date and '2011-08-31'::date;
+                                   QUERY PLAN                                    
+---------------------------------------------------------------------------------
+ Result
+   ->  Append
+         ->  Seq Scan on nv_parent
+               Filter: ((d >= '08-01-2011'::date) AND (d <= '08-31-2011'::date))
+         ->  Seq Scan on nv_child_2010 nv_parent
+               Filter: ((d >= '08-01-2011'::date) AND (d <= '08-31-2011'::date))
+         ->  Seq Scan on nv_child_2011 nv_parent
+               Filter: ((d >= '08-01-2011'::date) AND (d <= '08-31-2011'::date))
+(8 rows)
+
+explain (costs off) select * from nv_parent where d between '2009-08-01'::date and '2009-08-31'::date;
+                                   QUERY PLAN                                    
+---------------------------------------------------------------------------------
+ Result
+   ->  Append
+         ->  Seq Scan on nv_parent
+               Filter: ((d >= '08-01-2009'::date) AND (d <= '08-31-2009'::date))
+         ->  Seq Scan on nv_child_2010 nv_parent
+               Filter: ((d >= '08-01-2009'::date) AND (d <= '08-31-2009'::date))
+         ->  Seq Scan on nv_child_2011 nv_parent
+               Filter: ((d >= '08-01-2009'::date) AND (d <= '08-31-2009'::date))
+         ->  Seq Scan on nv_child_2009 nv_parent
+               Filter: ((d >= '08-01-2009'::date) AND (d <= '08-31-2009'::date))
+(10 rows)
+
+-- after validation, the constraint should be used
+alter table nv_child_2011 VALIDATE CONSTRAINT nv_child_2011_d_check;
+explain (costs off) select * from nv_parent where d between '2009-08-01'::date and '2009-08-31'::date;
+                                   QUERY PLAN                                    
+---------------------------------------------------------------------------------
+ Result
+   ->  Append
+         ->  Seq Scan on nv_parent
+               Filter: ((d >= '08-01-2009'::date) AND (d <= '08-31-2009'::date))
+         ->  Seq Scan on nv_child_2010 nv_parent
+               Filter: ((d >= '08-01-2009'::date) AND (d <= '08-31-2009'::date))
+         ->  Seq Scan on nv_child_2009 nv_parent
+               Filter: ((d >= '08-01-2009'::date) AND (d <= '08-31-2009'::date))
+(8 rows)
+
 -- Foreign key adding test with mixed types
 -- Note: these tables are TEMP to avoid name conflicts when this test
 -- is run in parallel with foreign_key.sql.

src/test/regress/expected/domain.out

@@ -352,6 +352,17 @@ alter domain con drop constraint t;
 insert into domcontest values (-5); --fails
 ERROR:  value for domain con violates check constraint "con_check"
 insert into domcontest values (42);
+-- Test ALTER DOMAIN .. CONSTRAINT .. NOT VALID
+create domain things AS INT;
+CREATE TABLE thethings (stuff things);
+INSERT INTO thethings (stuff) VALUES (55);
+ALTER DOMAIN things ADD CONSTRAINT meow CHECK (VALUE < 11);
+ERROR:  column "stuff" of table "thethings" contains values that violate the new constraint
+ALTER DOMAIN things ADD CONSTRAINT meow CHECK (VALUE < 11) NOT VALID;
+ALTER DOMAIN things VALIDATE CONSTRAINT meow;
+ERROR:  column "stuff" of table "thethings" contains values that violate the new constraint
+UPDATE thethings SET stuff = 10;
+ALTER DOMAIN things VALIDATE CONSTRAINT meow;
 -- Confirm ALTER DOMAIN with RULES.
 create table domtab (col1 integer);
 create domain dom as integer;

src/test/regress/sql/alter_table.sql

@@ -236,12 +236,41 @@ DELETE FROM tmp3 where a=5;
 ALTER TABLE tmp3 validate constraint tmpconstr;
 ALTER TABLE tmp3 validate constraint tmpconstr;
 
+-- Try a non-verified CHECK constraint
+ALTER TABLE tmp3 ADD CONSTRAINT b_greater_than_ten CHECK (b > 10); -- fail
+ALTER TABLE tmp3 ADD CONSTRAINT b_greater_than_ten CHECK (b > 10) NOT VALID; -- succeeds
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_greater_than_ten; -- fails
+DELETE FROM tmp3 WHERE NOT b > 10;
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_greater_than_ten; -- succeeds
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_greater_than_ten; -- succeeds
+
+-- Test inherited NOT VALID CHECK constraints
+select * from tmp3;
+CREATE TABLE tmp6 () INHERITS (tmp3);
+CREATE TABLE tmp7 () INHERITS (tmp3);
+
+INSERT INTO tmp6 VALUES (6, 30), (7, 16);
+ALTER TABLE tmp3 ADD CONSTRAINT b_le_20 CHECK (b <= 20) NOT VALID;
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_le_20;	-- fails
+DELETE FROM tmp6 WHERE b > 20;
+ALTER TABLE tmp3 VALIDATE CONSTRAINT b_le_20;	-- succeeds
+
+-- An already validated constraint must not be revalidated
+CREATE FUNCTION boo(int) RETURNS int IMMUTABLE STRICT LANGUAGE plpgsql AS $$ BEGIN RAISE NOTICE 'boo: %', $1; RETURN $1; END; $$;
+INSERT INTO tmp7 VALUES (8, 18);
+ALTER TABLE tmp7 ADD CONSTRAINT identity CHECK (b = boo(b));
+ALTER TABLE tmp3 ADD CONSTRAINT IDENTITY check (b = boo(b)) NOT VALID;
+ALTER TABLE tmp3 VALIDATE CONSTRAINT identity;
 
 -- Try (and fail) to create constraint from tmp5(a) to tmp4(a) - unique constraint on
 -- tmp4 is a,b
 
 ALTER TABLE tmp5 add constraint tmpconstr foreign key(a) references tmp4(a) match full;
 
+DROP TABLE tmp7;
+
+DROP TABLE tmp6;
+
 DROP TABLE tmp5;
 
 DROP TABLE tmp4;
@@ -250,6 +279,23 @@ DROP TABLE tmp3;
 
 DROP TABLE tmp2;
 
+-- NOT VALID with plan invalidation -- ensure we don't use a constraint for
+-- exclusion until validated
+set constraint_exclusion TO 'partition';
+create table nv_parent (d date); 
+create table nv_child_2010 () inherits (nv_parent);
+create table nv_child_2011 () inherits (nv_parent);
+alter table nv_child_2010 add check (d between '2010-01-01'::date and '2010-12-31'::date) not valid;
+alter table nv_child_2011 add check (d between '2011-01-01'::date and '2011-12-31'::date) not valid;
+explain (costs off) select * from nv_parent where d between '2011-08-01' and '2011-08-31';
+create table nv_child_2009 (check (d between '2009-01-01'::date and '2009-12-31'::date)) inherits (nv_parent);
+explain (costs off) select * from nv_parent where d between '2011-08-01'::date and '2011-08-31'::date;
+explain (costs off) select * from nv_parent where d between '2009-08-01'::date and '2009-08-31'::date;
+-- after validation, the constraint should be used
+alter table nv_child_2011 VALIDATE CONSTRAINT nv_child_2011_d_check;
+explain (costs off) select * from nv_parent where d between '2009-08-01'::date and '2009-08-31'::date;
+
+
 -- Foreign key adding test with mixed types
 
 -- Note: these tables are TEMP to avoid name conflicts when this test

src/test/regress/sql/domain.sql

@@ -259,6 +259,16 @@ alter domain con drop constraint t;
 insert into domcontest values (-5); --fails
 insert into domcontest values (42);
 
+-- Test ALTER DOMAIN .. CONSTRAINT .. NOT VALID
+create domain things AS INT;
+CREATE TABLE thethings (stuff things);
+INSERT INTO thethings (stuff) VALUES (55);
+ALTER DOMAIN things ADD CONSTRAINT meow CHECK (VALUE < 11);
+ALTER DOMAIN things ADD CONSTRAINT meow CHECK (VALUE < 11) NOT VALID;
+ALTER DOMAIN things VALIDATE CONSTRAINT meow;
+UPDATE thethings SET stuff = 10;
+ALTER DOMAIN things VALIDATE CONSTRAINT meow;
+
 -- Confirm ALTER DOMAIN with RULES.
 create table domtab (col1 integer);
 create domain dom as integer;