Add the notion of REPLICA IDENTITY for a table.

Pending patches for logical replication will use this to determine
which columns of a tuple ought to be considered as its candidate key.

Andres Freund, with minor, mostly cosmetic adjustments by me

doc/src/sgml/catalogs.sgml

@@ -1862,6 +1862,19 @@
        relations other than some materialized views)</entry>
      </row>
 
+     <row>
+      <entry><structfield>relreplident</structfield></entry>
+      <entry><type>char</type></entry>
+      <entry></entry>
+      <entry>
+       Columns used to form <quote>replica identity</> for rows:
+       <literal>d</> = default (primary key, if any),
+       <literal>n</> = nothing,
+       <literal>f</> = all columns
+       <literal>i</> = index with indisreplident set, or default
+      </entry>
+     </row>
+
      <row>
       <entry><structfield>relfrozenxid</structfield></entry>
       <entry><type>xid</type></entry>
@@ -3657,6 +3670,17 @@
       </entry>
      </row>
 
+     <row>
+      <entry><structfield>indisreplident</structfield></entry>
+      <entry><type>bool</type></entry>
+      <entry></entry>
+      <entry>
+       If true this index has been chosen as <quote>replica identity</>
+       using <command>ALTER TABLE ... REPLICA IDENTITY USING INDEX
+       ...</>
+      </entry>
+     </row>
+
      <row>
       <entry><structfield>indkey</structfield></entry>
       <entry><type>int2vector</type></entry>

doc/src/sgml/ref/alter_table.sgml

@@ -69,6 +69,7 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="PARAMETER">name</replaceable>
     NOT OF
     OWNER TO <replaceable class="PARAMETER">new_owner</replaceable>
     SET TABLESPACE <replaceable class="PARAMETER">new_tablespace</replaceable>
+    REPLICA IDENTITY {DEFAULT | USING INDEX <replaceable class="PARAMETER">index_name</replaceable> | FULL | NOTHING}
 
 <phrase>and <replaceable class="PARAMETER">table_constraint_using_index</replaceable> is:</phrase>
 
@@ -579,6 +580,24 @@ ALTER TABLE [ IF EXISTS ] <replaceable class="PARAMETER">name</replaceable>
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term><literal>REPLICA IDENTITY</literal></term>
+    <listitem>
+     <para>
+      This form changes the information which is written to the write-ahead log
+      to identify rows which are updated or deleted.  This option has no effect
+      except when logical replication is in use.  <literal>DEFAULT</> records the 
+      old values of the columns of the primary key, if any.  <literal>USING INDEX</>
+      records the old values of the columns covered by the named index, which
+      must be unique, not partial, not deferrable, and include only columns marked
+      <literal>NOT NULL</>.  <literal>FULL</> records the old values of all columns
+      in the row.  <literal>NOTHING</> records no information about the old row.
+      In all cases, no old values are logged unless at least one of the columns
+      that would be logged differs between the old and new versions of the row.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term><literal>RENAME</literal></term>
     <listitem>

src/backend/catalog/heap.c

@@ -793,6 +793,7 @@ InsertPgClassTuple(Relation pg_class_desc,
 	values[Anum_pg_class_relhastriggers - 1] = BoolGetDatum(rd_rel->relhastriggers);
 	values[Anum_pg_class_relhassubclass - 1] = BoolGetDatum(rd_rel->relhassubclass);
 	values[Anum_pg_class_relispopulated - 1] = BoolGetDatum(rd_rel->relispopulated);
+	values[Anum_pg_class_relreplident - 1] = CharGetDatum(rd_rel->relreplident);
 	values[Anum_pg_class_relfrozenxid - 1] = TransactionIdGetDatum(rd_rel->relfrozenxid);
 	values[Anum_pg_class_relminmxid - 1] = MultiXactIdGetDatum(rd_rel->relminmxid);
 	if (relacl != (Datum) 0)

src/backend/catalog/index.c

@@ -614,6 +614,7 @@ UpdateIndexRelation(Oid indexoid,
 	/* we set isvalid and isready the same way */
 	values[Anum_pg_index_indisready - 1] = BoolGetDatum(isvalid);
 	values[Anum_pg_index_indislive - 1] = BoolGetDatum(true);
+	values[Anum_pg_index_indisreplident - 1] = BoolGetDatum(false);
 	values[Anum_pg_index_indkey - 1] = PointerGetDatum(indkey);
 	values[Anum_pg_index_indcollation - 1] = PointerGetDatum(indcollation);
 	values[Anum_pg_index_indclass - 1] = PointerGetDatum(indclass);

src/backend/commands/tablecmds.c

@@ -399,6 +399,7 @@ static void ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
 static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid);
 static void ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode);
 static void ATExecDropOf(Relation rel, LOCKMODE lockmode);
+static void ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode);
 static void ATExecGenericOptions(Relation rel, List *options);
 
 static void copy_relation_data(SMgrRelation rel, SMgrRelation dst,
@@ -2809,6 +2810,7 @@ AlterTableGetLockLevel(List *cmds)
 			case AT_DisableTrigUser:
 			case AT_AddIndex:	/* from ADD CONSTRAINT */
 			case AT_AddIndexConstraint:
+			case AT_ReplicaIdentity:
 				cmd_lockmode = ShareRowExclusiveLock;
 				break;
 
@@ -3140,6 +3142,12 @@ ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
 				cmd->subtype = AT_ValidateConstraintRecurse;
 			pass = AT_PASS_MISC;
 			break;
+		case AT_ReplicaIdentity: /* REPLICA IDENTITY ... */
+			ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW);
+			pass = AT_PASS_MISC;
+			/* This command never recurses */
+			/* No command-specific prep needed */
+			break;
 		case AT_EnableTrig:		/* ENABLE TRIGGER variants */
 		case AT_EnableAlwaysTrig:
 		case AT_EnableReplicaTrig:
@@ -3440,6 +3448,9 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
 		case AT_DropOf:
 			ATExecDropOf(rel, lockmode);
 			break;
+		case AT_ReplicaIdentity:
+			ATExecReplicaIdentity(rel, (ReplicaIdentityStmt *) cmd->def, lockmode);
+			break;
 		case AT_GenericOptions:
 			ATExecGenericOptions(rel, (List *) cmd->def);
 			break;
@@ -10009,6 +10020,217 @@ ATExecDropOf(Relation rel, LOCKMODE lockmode)
 	heap_close(relationRelation, RowExclusiveLock);
 }
 
+/*
+ * relation_mark_replica_identity: Update a table's replica identity
+ *
+ * Iff ri_type = REPLICA_IDENTITY_INDEX, indexOid must be the Oid of a suitable
+ * index. Otherwise, it should be InvalidOid.
+ */
+static void
+relation_mark_replica_identity(Relation rel, char ri_type, Oid indexOid,
+							   bool is_internal)
+{
+	Relation	pg_index;
+	Relation	pg_class;
+	HeapTuple	pg_class_tuple;
+	HeapTuple	pg_index_tuple;
+	Form_pg_class pg_class_form;
+	Form_pg_index pg_index_form;
+
+	ListCell   *index;
+
+	/*
+	 * Check whether relreplident has changed, and update it if so.
+	 */
+	pg_class = heap_open(RelationRelationId, RowExclusiveLock);
+	pg_class_tuple = SearchSysCacheCopy1(RELOID,
+	                                     ObjectIdGetDatum(RelationGetRelid(rel)));
+	if (!HeapTupleIsValid(pg_class_tuple))
+		elog(ERROR, "cache lookup failed for relation \"%s\"",
+		     RelationGetRelationName(rel));
+	pg_class_form = (Form_pg_class) GETSTRUCT(pg_class_tuple);
+	if (pg_class_form->relreplident != ri_type)
+	{
+		pg_class_form->relreplident = ri_type;
+		simple_heap_update(pg_class, &pg_class_tuple->t_self, pg_class_tuple);
+		CatalogUpdateIndexes(pg_class, pg_class_tuple);
+	}
+	heap_close(pg_class, RowExclusiveLock);
+	heap_freetuple(pg_class_tuple);
+
+	/*
+	 * Check whether the correct index is marked indisreplident; if so, we're
+	 * done.
+	 */
+	if (OidIsValid(indexOid))
+	{
+		Assert(ri_type == REPLICA_IDENTITY_INDEX);
+
+		pg_index_tuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexOid));
+		if (!HeapTupleIsValid(pg_index_tuple))
+			elog(ERROR, "cache lookup failed for index %u", indexOid);
+		pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple);
+
+		if (pg_index_form->indisreplident)
+		{
+			ReleaseSysCache(pg_index_tuple);
+			return;
+		}
+		ReleaseSysCache(pg_index_tuple);
+	}
+
+	/*
+	 * Clear the indisreplident flag from any index that had it previously, and
+	 * set it for any index that should have it now.
+	 */
+	pg_index = heap_open(IndexRelationId, RowExclusiveLock);
+	foreach(index, RelationGetIndexList(rel))
+	{
+		Oid			thisIndexOid = lfirst_oid(index);
+		bool		dirty = false;
+
+		pg_index_tuple = SearchSysCacheCopy1(INDEXRELID,
+										 ObjectIdGetDatum(thisIndexOid));
+		if (!HeapTupleIsValid(pg_index_tuple))
+			elog(ERROR, "cache lookup failed for index %u", thisIndexOid);
+		pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple);
+
+		/*
+		 * Unset the bit if set.  We know it's wrong because we checked this
+		 * earlier.
+		 */
+		if (pg_index_form->indisreplident)
+		{
+			dirty = true;
+			pg_index_form->indisreplident = false;
+		}
+		else if (thisIndexOid == indexOid)
+		{
+			dirty = true;
+			pg_index_form->indisreplident = true;
+		}
+
+		if (dirty)
+		{
+			simple_heap_update(pg_index, &pg_index_tuple->t_self, pg_index_tuple);
+			CatalogUpdateIndexes(pg_index, pg_index_tuple);
+			InvokeObjectPostAlterHookArg(IndexRelationId, thisIndexOid, 0,
+			                             InvalidOid, is_internal);
+		}
+		heap_freetuple(pg_index_tuple);
+	}
+
+	heap_close(pg_index, RowExclusiveLock);
+}
+
+/*
+ * ALTER TABLE <name> REPLICA IDENTITY ...
+ */
+static void
+ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode)
+{
+	Oid			indexOid;
+	Relation	indexRel;
+	int			key;
+
+	if (stmt->identity_type == REPLICA_IDENTITY_DEFAULT)
+	{
+		relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
+		return;
+	}
+	else if (stmt->identity_type == REPLICA_IDENTITY_FULL)
+	{
+		relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
+		return;
+	}
+	else if (stmt->identity_type == REPLICA_IDENTITY_NOTHING)
+	{
+		relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
+		return;
+	}
+	else if (stmt->identity_type == REPLICA_IDENTITY_INDEX)
+	{
+		/* fallthrough */;
+	}
+	else
+		elog(ERROR, "unexpected identity type %u", stmt->identity_type);
+
+
+	/* Check that the index exists */
+	indexOid = get_relname_relid(stmt->name, rel->rd_rel->relnamespace);
+	if (!OidIsValid(indexOid))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("index \"%s\" for table \"%s\" does not exist",
+						stmt->name, RelationGetRelationName(rel))));
+
+	indexRel = index_open(indexOid, ShareLock);
+
+	/* Check that the index is on the relation we're altering. */
+	if (indexRel->rd_index == NULL ||
+		indexRel->rd_index->indrelid != RelationGetRelid(rel))
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("\"%s\" is not an index for table \"%s\"",
+						RelationGetRelationName(indexRel),
+						RelationGetRelationName(rel))));
+	/* The AM must support uniqueness, and the index must in fact be unique. */
+	if (!indexRel->rd_am->amcanunique || !indexRel->rd_index->indisunique)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("cannot use non-unique index \"%s\" as replica identity",
+						RelationGetRelationName(indexRel))));
+	/* Deferred indexes are not guaranteed to be always unique. */
+	if (!indexRel->rd_index->indimmediate)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot use non-immediate index \"%s\" as replica identity",
+						RelationGetRelationName(indexRel))));
+	/* Expression indexes aren't supported. */
+	if (RelationGetIndexExpressions(indexRel) != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot use expression index \"%s\" as replica identity",
+						RelationGetRelationName(indexRel))));
+	/* Predicate indexes aren't supported. */
+	if (RelationGetIndexPredicate(indexRel) != NIL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot use partial index \"%s\" as replica identity",
+						RelationGetRelationName(indexRel))));
+	/* And neither are invalid indexes. */
+	if (!IndexIsValid(indexRel->rd_index))
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("cannot use invalid index \"%s\" as replica identity",
+						RelationGetRelationName(indexRel))));
+
+	/* Check index for nullable columns. */
+	for (key = 0; key < indexRel->rd_index->indnatts; key++)
+	{
+		int16 attno = indexRel->rd_index->indkey.values[key];
+		Form_pg_attribute attr;
+
+		/* Of the system columns, only oid is indexable. */
+		if (attno <= 0 && attno != ObjectIdAttributeNumber)
+			elog(ERROR, "internal column %u in unique index \"%s\"",
+			     attno, RelationGetRelationName(indexRel));
+
+		attr = rel->rd_att->attrs[attno - 1];
+		if (!attr->attnotnull)
+			ereport(ERROR,
+			        (errcode(ERRCODE_WRONG_OBJECT_TYPE),
+			         errmsg("index \"%s\" cannot be used as replica identity because column \"%s\" is nullable",
+			                RelationGetRelationName(indexRel),
+			                NameStr(attr->attname))));
+	}
+
+	/* This index is suitable for use as a replica identity. Mark it. */
+	relation_mark_replica_identity(rel, stmt->identity_type, indexOid, true);
+
+	index_close(indexRel, NoLock);
+}
+
 /*
  * ALTER FOREIGN TABLE <name> OPTIONS (...)
  */

src/backend/nodes/copyfuncs.c

@@ -3270,6 +3270,17 @@ _copyRefreshMatViewStmt(const RefreshMatViewStmt *from)
 	return newnode;
 }
 
+static ReplicaIdentityStmt *
+_copyReplicaIdentityStmt(const ReplicaIdentityStmt *from)
+{
+	ReplicaIdentityStmt *newnode = makeNode(ReplicaIdentityStmt);
+
+	COPY_SCALAR_FIELD(identity_type);
+	COPY_STRING_FIELD(name);
+
+	return newnode;
+}
+
 static CreateSeqStmt *
 _copyCreateSeqStmt(const CreateSeqStmt *from)
 {
@@ -4343,6 +4354,9 @@ copyObject(const void *from)
 		case T_RefreshMatViewStmt:
 			retval = _copyRefreshMatViewStmt(from);
 			break;
+		case T_ReplicaIdentityStmt:
+			retval = _copyReplicaIdentityStmt(from);
+			break;
 		case T_CreateSeqStmt:
 			retval = _copyCreateSeqStmt(from);
 			break;

src/backend/nodes/equalfuncs.c

@@ -1537,6 +1537,15 @@ _equalRefreshMatViewStmt(const RefreshMatViewStmt *a, const RefreshMatViewStmt *
 	return true;
 }
 
+static bool
+_equalReplicaIdentityStmt(const ReplicaIdentityStmt *a, const ReplicaIdentityStmt *b)
+{
+	COMPARE_SCALAR_FIELD(identity_type);
+	COMPARE_STRING_FIELD(name);
+
+	return true;
+}
+
 static bool
 _equalCreateSeqStmt(const CreateSeqStmt *a, const CreateSeqStmt *b)
 {
@@ -2813,6 +2822,9 @@ equal(const void *a, const void *b)
 		case T_RefreshMatViewStmt:
 			retval = _equalRefreshMatViewStmt(a, b);
 			break;
+		case T_ReplicaIdentityStmt:
+			retval = _equalReplicaIdentityStmt(a, b);
+			break;
 		case T_CreateSeqStmt:
 			retval = _equalCreateSeqStmt(a, b);
 			break;

src/backend/parser/gram.y

@@ -255,6 +255,7 @@ static Node *makeRecursiveViewSelect(char *relname, List *aliases, Node *query);
 %type <ival>	add_drop opt_asc_desc opt_nulls_order
 
 %type <node>	alter_table_cmd alter_type_cmd opt_collate_clause
+	   replica_identity
 %type <list>	alter_table_cmds alter_type_cmds
 
 %type <dbehavior>	opt_drop_behavior
@@ -2178,6 +2179,14 @@ alter_table_cmd:
 					n->def = (Node *)$2;
 					$$ = (Node *)n;
 				}
+			/* ALTER TABLE <name> REPLICA IDENTITY  */
+			| REPLICA IDENTITY_P replica_identity
+				{
+					AlterTableCmd *n = makeNode(AlterTableCmd);
+					n->subtype = AT_ReplicaIdentity;
+					n->def = $3;
+					$$ = (Node *)n;
+				}
 			| alter_generic_options
 				{
 					AlterTableCmd *n = makeNode(AlterTableCmd);
@@ -2215,6 +2224,37 @@ alter_using:
 			| /* EMPTY */				{ $$ = NULL; }
 		;
 
+replica_identity:
+			NOTHING
+				{
+					ReplicaIdentityStmt *n = makeNode(ReplicaIdentityStmt);
+					n->identity_type = REPLICA_IDENTITY_NOTHING;
+					n->name = NULL;
+					$$ = (Node *) n;
+				}
+			| FULL
+				{
+					ReplicaIdentityStmt *n = makeNode(ReplicaIdentityStmt);
+					n->identity_type = REPLICA_IDENTITY_FULL;
+					n->name = NULL;
+					$$ = (Node *) n;
+				}
+			| DEFAULT
+				{
+					ReplicaIdentityStmt *n = makeNode(ReplicaIdentityStmt);
+					n->identity_type = REPLICA_IDENTITY_DEFAULT;
+					n->name = NULL;
+					$$ = (Node *) n;
+				}
+			| USING INDEX name
+				{
+					ReplicaIdentityStmt *n = makeNode(ReplicaIdentityStmt);
+					n->identity_type = REPLICA_IDENTITY_INDEX;
+					n->name = $3;
+					$$ = (Node *) n;
+				}
+;
+
 reloptions:
 			'(' reloption_list ')'					{ $$ = $2; }
 		;

src/backend/utils/cache/relcache.c

@@ -1454,6 +1454,7 @@ formrdesc(const char *relationName, Oid relationReltype,
 	/* ... and they're always populated, too */
 	relation->rd_rel->relispopulated = true;
 
+	relation->rd_rel->relreplident = REPLICA_IDENTITY_NOTHING;
 	relation->rd_rel->relpages = 0;
 	relation->rd_rel->reltuples = 0;
 	relation->rd_rel->relallvisible = 0;
@@ -2664,6 +2665,13 @@ RelationBuildLocalRelation(const char *relname,
 	else
 		rel->rd_rel->relispopulated = true;
 
+	/* system relations and non-table objects don't have one */
+	if (!IsSystemNamespace(relnamespace) &&
+	    (relkind == RELKIND_RELATION || relkind == RELKIND_MATVIEW))
+		rel->rd_rel->relreplident = REPLICA_IDENTITY_DEFAULT;
+	else
+		rel->rd_rel->relreplident = REPLICA_IDENTITY_NOTHING;
+
 	/*
 	 * Insert relation physical and logical identifiers (OIDs) into the right
 	 * places.	For a mapped relation, we set relfilenode to zero and rely on
@@ -3462,7 +3470,10 @@ RelationGetIndexList(Relation relation)
 	ScanKeyData skey;
 	HeapTuple	htup;
 	List	   *result;
-	Oid			oidIndex;
+	char		replident = relation->rd_rel->relreplident;
+	Oid			oidIndex = InvalidOid;
+	Oid			pkeyIndex = InvalidOid;
+	Oid			candidateIndex = InvalidOid;
 	MemoryContext oldcxt;
 
 	/* Quick exit if we already computed the list. */
@@ -3519,17 +3530,45 @@ RelationGetIndexList(Relation relation)
 		Assert(!isnull);
 		indclass = (oidvector *) DatumGetPointer(indclassDatum);
 
-		/* Check to see if it is a unique, non-partial btree index on OID */
-		if (IndexIsValid(index) &&
-			index->indnatts == 1 &&
-			index->indisunique && index->indimmediate &&
+		/*
+		 * Invalid, non-unique, non-immediate or predicate indexes aren't
+		 * interesting for neither oid indexes nor replication identity
+		 * indexes, so don't check them.
+		 */
+		if (!IndexIsValid(index) || !index->indisunique ||
+			!index->indimmediate ||
+			!heap_attisnull(htup, Anum_pg_index_indpred))
+			continue;
+
+		/* Check to see if is a usable btree index on OID */
+		if (index->indnatts == 1 &&
 			index->indkey.values[0] == ObjectIdAttributeNumber &&
-			indclass->values[0] == OID_BTREE_OPS_OID &&
-			heap_attisnull(htup, Anum_pg_index_indpred))
+			indclass->values[0] == OID_BTREE_OPS_OID)
 			oidIndex = index->indexrelid;
+
+		/* always prefer primary keys */
+		if (index->indisprimary)
+			pkeyIndex = index->indexrelid;
+
+		/* explicitly chosen index */
+		if (index->indisreplident)
+			candidateIndex = index->indexrelid;
 	}
 
 	systable_endscan(indscan);
+
+	/* primary key */
+	if (replident == REPLICA_IDENTITY_DEFAULT &&
+		OidIsValid(pkeyIndex))
+		relation->rd_replidindex = pkeyIndex;
+	/* explicitly chosen index */
+	else if (replident == REPLICA_IDENTITY_INDEX &&
+			 OidIsValid(candidateIndex))
+		relation->rd_replidindex = candidateIndex;
+	/* nothing */
+	else
+		relation->rd_replidindex = InvalidOid;
+
 	heap_close(indrel, AccessShareLock);
 
 	/* Now save a copy of the completed list in the relcache entry. */

src/bin/pg_dump/pg_dump.c

@@ -4221,6 +4221,7 @@ getTables(Archive *fout, int *numTables)
 	int			i_toastfrozenxid;
 	int			i_relpersistence;
 	int			i_relispopulated;
+	int			i_relreplident;
 	int			i_owning_tab;
 	int			i_owning_col;
 	int			i_reltablespace;
@@ -4253,7 +4254,7 @@ getTables(Archive *fout, int *numTables)
 	 * we cannot correctly identify inherited columns, owned sequences, etc.
 	 */
 
-	if (fout->remoteVersion >= 90300)
+	if (fout->remoteVersion >= 90400)
 	{
 		/*
 		 * Left join to pick up dependency info linking sequences to their
@@ -4268,7 +4269,46 @@ getTables(Archive *fout, int *numTables)
 						  "c.relfrozenxid, tc.oid AS toid, "
 						  "tc.relfrozenxid AS tfrozenxid, "
 						  "c.relpersistence, c.relispopulated, "
-						  "c.relpages, "
+						  "c.relreplident, c.relpages, "
+						  "CASE WHEN c.reloftype <> 0 THEN c.reloftype::pg_catalog.regtype ELSE NULL END AS reloftype, "
+						  "d.refobjid AS owning_tab, "
+						  "d.refobjsubid AS owning_col, "
+						  "(SELECT spcname FROM pg_tablespace t WHERE t.oid = c.reltablespace) AS reltablespace, "
+						"array_to_string(array_remove(array_remove(c.reloptions,'check_option=local'),'check_option=cascaded'), ', ') AS reloptions, "
+						  "CASE WHEN 'check_option=local' = ANY (c.reloptions) THEN 'LOCAL'::text "
+							   "WHEN 'check_option=cascaded' = ANY (c.reloptions) THEN 'CASCADED'::text ELSE NULL END AS checkoption, "
+						  "array_to_string(array(SELECT 'toast.' || x FROM unnest(tc.reloptions) x), ', ') AS toast_reloptions "
+						  "FROM pg_class c "
+						  "LEFT JOIN pg_depend d ON "
+						  "(c.relkind = '%c' AND "
+						  "d.classid = c.tableoid AND d.objid = c.oid AND "
+						  "d.objsubid = 0 AND "
+						  "d.refclassid = c.tableoid AND d.deptype = 'a') "
+					   "LEFT JOIN pg_class tc ON (c.reltoastrelid = tc.oid) "
+				   "WHERE c.relkind in ('%c', '%c', '%c', '%c', '%c', '%c') "
+						  "ORDER BY c.oid",
+						  username_subquery,
+						  RELKIND_SEQUENCE,
+						  RELKIND_RELATION, RELKIND_SEQUENCE,
+						  RELKIND_VIEW, RELKIND_COMPOSITE_TYPE,
+						  RELKIND_MATVIEW, RELKIND_FOREIGN_TABLE);
+	}
+	else if (fout->remoteVersion >= 90300)
+	{
+		/*
+		 * Left join to pick up dependency info linking sequences to their
+		 * owning column, if any (note this dependency is AUTO as of 8.2)
+		 */
+		appendPQExpBuffer(query,
+						  "SELECT c.tableoid, c.oid, c.relname, "
+						  "c.relacl, c.relkind, c.relnamespace, "
+						  "(%s c.relowner) AS rolname, "
+						  "c.relchecks, c.relhastriggers, "
+						  "c.relhasindex, c.relhasrules, c.relhasoids, "
+						  "c.relfrozenxid, tc.oid AS toid, "
+						  "tc.relfrozenxid AS tfrozenxid, "
+						  "c.relpersistence, c.relispopulated, "
+						  "'d' AS relreplident, c.relpages, "
 						  "CASE WHEN c.reloftype <> 0 THEN c.reloftype::pg_catalog.regtype ELSE NULL END AS reloftype, "
 						  "d.refobjid AS owning_tab, "
 						  "d.refobjsubid AS owning_col, "
@@ -4307,7 +4347,7 @@ getTables(Archive *fout, int *numTables)
 						  "c.relfrozenxid, tc.oid AS toid, "
 						  "tc.relfrozenxid AS tfrozenxid, "
 						  "c.relpersistence, 't' as relispopulated, "
-						  "c.relpages, "
+						  "'d' AS relreplident, c.relpages, "
 						  "CASE WHEN c.reloftype <> 0 THEN c.reloftype::pg_catalog.regtype ELSE NULL END AS reloftype, "
 						  "d.refobjid AS owning_tab, "
 						  "d.refobjsubid AS owning_col, "
@@ -4344,7 +4384,7 @@ getTables(Archive *fout, int *numTables)
 						  "c.relfrozenxid, tc.oid AS toid, "
 						  "tc.relfrozenxid AS tfrozenxid, "
 						  "'p' AS relpersistence, 't' as relispopulated, "
-						  "c.relpages, "
+						  "'d' AS relreplident, c.relpages, "
 						  "CASE WHEN c.reloftype <> 0 THEN c.reloftype::pg_catalog.regtype ELSE NULL END AS reloftype, "
 						  "d.refobjid AS owning_tab, "
 						  "d.refobjsubid AS owning_col, "
@@ -4380,7 +4420,7 @@ getTables(Archive *fout, int *numTables)
 						  "c.relfrozenxid, tc.oid AS toid, "
 						  "tc.relfrozenxid AS tfrozenxid, "
 						  "'p' AS relpersistence, 't' as relispopulated, "
-						  "c.relpages, "
+						  "'d' AS relreplident, c.relpages, "
 						  "NULL AS reloftype, "
 						  "d.refobjid AS owning_tab, "
 						  "d.refobjsubid AS owning_col, "
@@ -4416,7 +4456,7 @@ getTables(Archive *fout, int *numTables)
 						  "c.relfrozenxid, tc.oid AS toid, "
 						  "tc.relfrozenxid AS tfrozenxid, "
 						  "'p' AS relpersistence, 't' as relispopulated, "
-						  "c.relpages, "
+						  "'d' AS relreplident, c.relpages, "
 						  "NULL AS reloftype, "
 						  "d.refobjid AS owning_tab, "
 						  "d.refobjsubid AS owning_col, "
@@ -4453,7 +4493,7 @@ getTables(Archive *fout, int *numTables)
 						  "0 AS toid, "
 						  "0 AS tfrozenxid, "
 						  "'p' AS relpersistence, 't' as relispopulated, "
-						  "relpages, "
+						  "'d' AS relreplident, relpages, "
 						  "NULL AS reloftype, "
 						  "d.refobjid AS owning_tab, "
 						  "d.refobjsubid AS owning_col, "
@@ -4489,7 +4529,7 @@ getTables(Archive *fout, int *numTables)
 						  "0 AS toid, "
 						  "0 AS tfrozenxid, "
 						  "'p' AS relpersistence, 't' as relispopulated, "
-						  "relpages, "
+						  "'d' AS relreplident, relpages, "
 						  "NULL AS reloftype, "
 						  "d.refobjid AS owning_tab, "
 						  "d.refobjsubid AS owning_col, "
@@ -4521,7 +4561,7 @@ getTables(Archive *fout, int *numTables)
 						  "0 AS toid, "
 						  "0 AS tfrozenxid, "
 						  "'p' AS relpersistence, 't' as relispopulated, "
-						  "relpages, "
+						  "'d' AS relreplident, relpages, "
 						  "NULL AS reloftype, "
 						  "NULL::oid AS owning_tab, "
 						  "NULL::int4 AS owning_col, "
@@ -4548,7 +4588,7 @@ getTables(Archive *fout, int *numTables)
 						  "0 AS toid, "
 						  "0 AS tfrozenxid, "
 						  "'p' AS relpersistence, 't' as relispopulated, "
-						  "relpages, "
+						  "'d' AS relreplident, relpages, "
 						  "NULL AS reloftype, "
 						  "NULL::oid AS owning_tab, "
 						  "NULL::int4 AS owning_col, "
@@ -4585,7 +4625,7 @@ getTables(Archive *fout, int *numTables)
 						  "0 AS toid, "
 						  "0 AS tfrozenxid, "
 						  "'p' AS relpersistence, 't' as relispopulated, "
-						  "0 AS relpages, "
+						  "'d' AS relreplident, 0 AS relpages, "
 						  "NULL AS reloftype, "
 						  "NULL::oid AS owning_tab, "
 						  "NULL::int4 AS owning_col, "
@@ -4634,6 +4674,7 @@ getTables(Archive *fout, int *numTables)
 	i_toastfrozenxid = PQfnumber(res, "tfrozenxid");
 	i_relpersistence = PQfnumber(res, "relpersistence");
 	i_relispopulated = PQfnumber(res, "relispopulated");
+	i_relreplident = PQfnumber(res, "relreplident");
 	i_relpages = PQfnumber(res, "relpages");
 	i_owning_tab = PQfnumber(res, "owning_tab");
 	i_owning_col = PQfnumber(res, "owning_col");
@@ -4678,6 +4719,7 @@ getTables(Archive *fout, int *numTables)
 		tblinfo[i].hastriggers = (strcmp(PQgetvalue(res, i, i_relhastriggers), "t") == 0);
 		tblinfo[i].hasoids = (strcmp(PQgetvalue(res, i, i_relhasoids), "t") == 0);
 		tblinfo[i].relispopulated = (strcmp(PQgetvalue(res, i, i_relispopulated), "t") == 0);
+		tblinfo[i].relreplident = *(PQgetvalue(res, i, i_relreplident));
 		tblinfo[i].relpages = atoi(PQgetvalue(res, i, i_relpages));
 		tblinfo[i].frozenxid = atooid(PQgetvalue(res, i, i_relfrozenxid));
 		tblinfo[i].toast_oid = atooid(PQgetvalue(res, i, i_toastoid));
@@ -4863,6 +4905,7 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 				i_indnkeys,
 				i_indkey,
 				i_indisclustered,
+				i_indisreplident,
 				i_contype,
 				i_conname,
 				i_condeferrable,
@@ -4909,7 +4952,7 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 		 * is not.
 		 */
 		resetPQExpBuffer(query);
-		if (fout->remoteVersion >= 90000)
+		if (fout->remoteVersion >= 90400)
 		{
 			/*
 			 * the test on indisready is necessary in 9.2, and harmless in
@@ -4921,7 +4964,38 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 					 "pg_catalog.pg_get_indexdef(i.indexrelid) AS indexdef, "
 							  "t.relnatts AS indnkeys, "
 							  "i.indkey, i.indisclustered, "
-							  "t.relpages, "
+							  "i.indisreplident, t.relpages, "
+							  "c.contype, c.conname, "
+							  "c.condeferrable, c.condeferred, "
+							  "c.tableoid AS contableoid, "
+							  "c.oid AS conoid, "
+				  "pg_catalog.pg_get_constraintdef(c.oid, false) AS condef, "
+							  "(SELECT spcname FROM pg_catalog.pg_tablespace s WHERE s.oid = t.reltablespace) AS tablespace, "
+							"array_to_string(t.reloptions, ', ') AS options "
+							  "FROM pg_catalog.pg_index i "
+					  "JOIN pg_catalog.pg_class t ON (t.oid = i.indexrelid) "
+							  "LEFT JOIN pg_catalog.pg_constraint c "
+							  "ON (i.indrelid = c.conrelid AND "
+							  "i.indexrelid = c.conindid AND "
+							  "c.contype IN ('p','u','x')) "
+							  "WHERE i.indrelid = '%u'::pg_catalog.oid "
+							  "AND i.indisvalid AND i.indisready "
+							  "ORDER BY indexname",
+							  tbinfo->dobj.catId.oid);
+		}
+		else if (fout->remoteVersion >= 90000)
+		{
+			/*
+			 * the test on indisready is necessary in 9.2, and harmless in
+			 * earlier/later versions
+			 */
+			appendPQExpBuffer(query,
+							  "SELECT t.tableoid, t.oid, "
+							  "t.relname AS indexname, "
+					 "pg_catalog.pg_get_indexdef(i.indexrelid) AS indexdef, "
+							  "t.relnatts AS indnkeys, "
+							  "i.indkey, i.indisclustered, "
+							  "false AS indisreplident, t.relpages, "
 							  "c.contype, c.conname, "
 							  "c.condeferrable, c.condeferred, "
 							  "c.tableoid AS contableoid, "
@@ -4948,7 +5022,7 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 					 "pg_catalog.pg_get_indexdef(i.indexrelid) AS indexdef, "
 							  "t.relnatts AS indnkeys, "
 							  "i.indkey, i.indisclustered, "
-							  "t.relpages, "
+							  "false AS indisreplident, t.relpages, "
 							  "c.contype, c.conname, "
 							  "c.condeferrable, c.condeferred, "
 							  "c.tableoid AS contableoid, "
@@ -4978,7 +5052,7 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 					 "pg_catalog.pg_get_indexdef(i.indexrelid) AS indexdef, "
 							  "t.relnatts AS indnkeys, "
 							  "i.indkey, i.indisclustered, "
-							  "t.relpages, "
+							  "false AS indisreplident, t.relpages, "
 							  "c.contype, c.conname, "
 							  "c.condeferrable, c.condeferred, "
 							  "c.tableoid AS contableoid, "
@@ -5007,7 +5081,7 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 					 "pg_catalog.pg_get_indexdef(i.indexrelid) AS indexdef, "
 							  "t.relnatts AS indnkeys, "
 							  "i.indkey, i.indisclustered, "
-							  "t.relpages, "
+							  "false AS indisreplident, t.relpages, "
 							  "c.contype, c.conname, "
 							  "c.condeferrable, c.condeferred, "
 							  "c.tableoid AS contableoid, "
@@ -5036,7 +5110,7 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 							  "pg_get_indexdef(i.indexrelid) AS indexdef, "
 							  "t.relnatts AS indnkeys, "
 							  "i.indkey, false AS indisclustered, "
-							  "t.relpages, "
+							  "false AS indisreplident, t.relpages, "
 							  "CASE WHEN i.indisprimary THEN 'p'::char "
 							  "ELSE '0'::char END AS contype, "
 							  "t.relname AS conname, "
@@ -5063,7 +5137,7 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 							  "pg_get_indexdef(i.indexrelid) AS indexdef, "
 							  "t.relnatts AS indnkeys, "
 							  "i.indkey, false AS indisclustered, "
-							  "t.relpages, "
+							  "false AS indisreplident, t.relpages, "
 							  "CASE WHEN i.indisprimary THEN 'p'::char "
 							  "ELSE '0'::char END AS contype, "
 							  "t.relname AS conname, "
@@ -5092,6 +5166,7 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 		i_indnkeys = PQfnumber(res, "indnkeys");
 		i_indkey = PQfnumber(res, "indkey");
 		i_indisclustered = PQfnumber(res, "indisclustered");
+		i_indisreplident = PQfnumber(res, "indisreplident");
 		i_relpages = PQfnumber(res, "relpages");
 		i_contype = PQfnumber(res, "contype");
 		i_conname = PQfnumber(res, "conname");
@@ -5135,6 +5210,7 @@ getIndexes(Archive *fout, TableInfo tblinfo[], int numTables)
 			parseOidArray(PQgetvalue(res, j, i_indkey),
 						  indxinfo[j].indkeys, INDEX_MAX_KEYS);
 			indxinfo[j].indisclustered = (PQgetvalue(res, j, i_indisclustered)[0] == 't');
+			indxinfo[j].indisreplident = (PQgetvalue(res, j, i_indisreplident)[0] == 't');
 			indxinfo[j].relpages = atoi(PQgetvalue(res, j, i_relpages));
 			contype = *(PQgetvalue(res, j, i_contype));
 
@@ -13408,6 +13484,28 @@ dumpTableSchema(Archive *fout, TableInfo *tbinfo)
 		}
 	}
 
+	/*
+	 * dump properties we only have ALTER TABLE syntax for
+	 */
+	if ((tbinfo->relkind == RELKIND_RELATION || tbinfo->relkind == RELKIND_MATVIEW) &&
+	    tbinfo->relreplident != REPLICA_IDENTITY_DEFAULT)
+	{
+		if (tbinfo->relreplident == REPLICA_IDENTITY_INDEX)
+		{
+			/* nothing to do, will be set when the index is dumped */
+		}
+		else if (tbinfo->relreplident == REPLICA_IDENTITY_NOTHING)
+		{
+			appendPQExpBuffer(q, "\nALTER TABLE ONLY %s REPLICA IDENTITY NOTHING;\n",
+			                  fmtId(tbinfo->dobj.name));
+		}
+		else if (tbinfo->relreplident == REPLICA_IDENTITY_FULL)
+		{
+			appendPQExpBuffer(q, "\nALTER TABLE ONLY %s REPLICA IDENTITY FULL;\n",
+			                  fmtId(tbinfo->dobj.name));
+		}
+	}
+
 	if (binary_upgrade)
 		binary_upgrade_extension_member(q, &tbinfo->dobj, labelq->data);
 
@@ -13579,6 +13677,15 @@ dumpIndex(Archive *fout, IndxInfo *indxinfo)
 							  fmtId(indxinfo->dobj.name));
 		}
 
+		/* If the index is clustered, we need to record that. */
+		if (indxinfo->indisreplident)
+		{
+			appendPQExpBuffer(q, "\nALTER TABLE ONLY %s REPLICA IDENTITY USING",
+			                  fmtId(tbinfo->dobj.name));
+			appendPQExpBuffer(q, " INDEX %s;\n",
+			                  fmtId(indxinfo->dobj.name));
+		}
+
 		/*
 		 * DROP must be fully qualified in case same name appears in
 		 * pg_catalog

src/bin/pg_dump/pg_dump.h

@@ -237,6 +237,7 @@ typedef struct _tableInfo
 	char		relkind;
 	char		relpersistence; /* relation persistence */
 	bool		relispopulated; /* relation is populated */
+	bool		relreplident;	/* replica identifier */
 	char	   *reltablespace;	/* relation tablespace */
 	char	   *reloptions;		/* options specified by WITH (...) */
 	char	   *checkoption;	/* WITH CHECK OPTION */
@@ -315,6 +316,7 @@ typedef struct _indxInfo
 	int			indnkeys;
 	Oid		   *indkeys;
 	bool		indisclustered;
+	bool		indisreplident;
 	/* if there is an associated constraint object, its dumpId: */
 	DumpId		indexconstraint;
 	int			relpages;		/* relpages of the underlying table */

src/bin/psql/describe.c

@@ -1156,6 +1156,7 @@ describeOneTableDetails(const char *schemaname,
 		char	   *reloptions;
 		char	   *reloftype;
 		char		relpersistence;
+		char		relreplident;
 	}			tableinfo;
 	bool		show_modifiers = false;
 	bool		retval;
@@ -1171,7 +1172,24 @@ describeOneTableDetails(const char *schemaname,
 	initPQExpBuffer(&tmpbuf);
 
 	/* Get general table info */
-	if (pset.sversion >= 90100)
+	if (pset.sversion >= 90400)
+	{
+		printfPQExpBuffer(&buf,
+			  "SELECT c.relchecks, c.relkind, c.relhasindex, c.relhasrules, "
+						  "c.relhastriggers, c.relhasoids, "
+						  "%s, c.reltablespace, "
+						  "CASE WHEN c.reloftype = 0 THEN '' ELSE c.reloftype::pg_catalog.regtype::pg_catalog.text END, "
+						  "c.relpersistence, c.relreplident\n"
+						  "FROM pg_catalog.pg_class c\n "
+		   "LEFT JOIN pg_catalog.pg_class tc ON (c.reltoastrelid = tc.oid)\n"
+						  "WHERE c.oid = '%s';",
+						  (verbose ?
+						   "pg_catalog.array_to_string(c.reloptions || "
+						   "array(select 'toast.' || x from pg_catalog.unnest(tc.reloptions) x), ', ')\n"
+						   : "''"),
+						  oid);
+	}
+	else if (pset.sversion >= 90100)
 	{
 		printfPQExpBuffer(&buf,
 			  "SELECT c.relchecks, c.relkind, c.relhasindex, c.relhasrules, "
@@ -1276,6 +1294,8 @@ describeOneTableDetails(const char *schemaname,
 		pg_strdup(PQgetvalue(res, 0, 8)) : NULL;
 	tableinfo.relpersistence = (pset.sversion >= 90100) ?
 		*(PQgetvalue(res, 0, 9)) : 0;
+	tableinfo.relreplident = (pset.sversion >= 90400) ?
+		*(PQgetvalue(res, 0, 10)) : 'd';
 	PQclear(res);
 	res = NULL;
 
@@ -1589,6 +1609,12 @@ describeOneTableDetails(const char *schemaname,
 		else
 			appendPQExpBuffer(&buf,
 						"  false AS condeferrable, false AS condeferred,\n");
+
+		if (pset.sversion >= 90400)
+			appendPQExpBuffer(&buf, "i.indisidentity,\n");
+		else
+			appendPQExpBuffer(&buf, "false AS indisidentity,\n");
+
 		appendPQExpBuffer(&buf, "  a.amname, c2.relname, "
 					  "pg_catalog.pg_get_expr(i.indpred, i.indrelid, true)\n"
 						  "FROM pg_catalog.pg_index i, pg_catalog.pg_class c, pg_catalog.pg_class c2, pg_catalog.pg_am a\n"
@@ -1612,9 +1638,10 @@ describeOneTableDetails(const char *schemaname,
 			char	   *indisvalid = PQgetvalue(result, 0, 3);
 			char	   *deferrable = PQgetvalue(result, 0, 4);
 			char	   *deferred = PQgetvalue(result, 0, 5);
-			char	   *indamname = PQgetvalue(result, 0, 6);
-			char	   *indtable = PQgetvalue(result, 0, 7);
-			char	   *indpred = PQgetvalue(result, 0, 8);
+			char	   *indisidentity = PQgetvalue(result, 0, 6);
+			char	   *indamname = PQgetvalue(result, 0, 7);
+			char	   *indtable = PQgetvalue(result, 0, 8);
+			char	   *indpred = PQgetvalue(result, 0, 9);
 
 			if (strcmp(indisprimary, "t") == 0)
 				printfPQExpBuffer(&tmpbuf, _("primary key, "));
@@ -1643,6 +1670,9 @@ describeOneTableDetails(const char *schemaname,
 			if (strcmp(deferred, "t") == 0)
 				appendPQExpBuffer(&tmpbuf, _(", initially deferred"));
 
+			if (strcmp(indisidentity, "t") == 0)
+				appendPQExpBuffer(&tmpbuf, _(", replica identity"));
+
 			printTableAddFooter(&cont, tmpbuf.data);
 			add_tablespace_footer(&cont, tableinfo.relkind,
 								  tableinfo.tablespace, true);
@@ -1713,6 +1743,10 @@ describeOneTableDetails(const char *schemaname,
 				appendPQExpBuffer(&buf,
 								  "null AS constraintdef, null AS contype, "
 							 "false AS condeferrable, false AS condeferred");
+			if (pset.sversion >= 90400)
+				appendPQExpBuffer(&buf, ", i.indisreplident");
+			else
+				appendPQExpBuffer(&buf, ", false AS indisreplident");
 			if (pset.sversion >= 80000)
 				appendPQExpBuffer(&buf, ", c2.reltablespace");
 			appendPQExpBuffer(&buf,
@@ -1783,12 +1817,15 @@ describeOneTableDetails(const char *schemaname,
 					if (strcmp(PQgetvalue(result, i, 4), "t") != 0)
 						appendPQExpBuffer(&buf, " INVALID");
 
+					if (strcmp(PQgetvalue(result, i, 10), "t") == 0)
+						appendPQExpBuffer(&buf, " REPLICA IDENTITY");
+
 					printTableAddFooter(&cont, buf.data);
 
 					/* Print tablespace of the index on the same line */
 					if (pset.sversion >= 80000)
 						add_tablespace_footer(&cont, 'i',
-										   atooid(PQgetvalue(result, i, 10)),
+										   atooid(PQgetvalue(result, i, 11)),
 											  false);
 				}
 			}
@@ -2273,6 +2310,17 @@ describeOneTableDetails(const char *schemaname,
 			printTableAddFooter(&cont, buf.data);
 		}
 
+		if ((tableinfo.relkind == 'r' || tableinfo.relkind == 'm') &&
+		    tableinfo.relreplident != 'd' && tableinfo.relreplident != 'i')
+		{
+			const char *s = _("Replica Identity");
+
+			printfPQExpBuffer(&buf, "%s: %s",
+			                  s,
+			                  tableinfo.relreplident == 'n' ? "NOTHING" : "FULL");
+			printTableAddFooter(&cont, buf.data);
+		}
+
 		/* OIDs, if verbose and not a materialized view */
 		if (verbose && tableinfo.relkind != 'm')
 		{

src/bin/psql/tab-complete.c

@@ -1336,7 +1336,7 @@ psql_completion(char *text, int start, int end)
 		static const char *const list_ALTER2[] =
 		{"ADD", "ALTER", "CLUSTER ON", "DISABLE", "DROP", "ENABLE", "INHERIT",
 			"NO INHERIT", "RENAME", "RESET", "OWNER TO", "SET",
-		"VALIDATE CONSTRAINT", NULL};
+		 "VALIDATE CONSTRAINT", "REPLICA IDENTITY", NULL};
 
 		COMPLETE_WITH_LIST(list_ALTER2);
 	}
@@ -1581,6 +1581,35 @@ psql_completion(char *text, int start, int end)
 
 		COMPLETE_WITH_LIST(list_TABLEOPTIONS);
 	}
+	else if (pg_strcasecmp(prev4_wd, "REPLICA") == 0 &&
+			 pg_strcasecmp(prev3_wd, "IDENTITY") == 0 &&
+			 pg_strcasecmp(prev2_wd, "USING") == 0 &&
+	         pg_strcasecmp(prev_wd, "INDEX") == 0)
+	{
+		completion_info_charp = prev5_wd;
+		COMPLETE_WITH_QUERY(Query_for_index_of_table);
+	}
+	else if (pg_strcasecmp(prev5_wd, "TABLE") == 0 &&
+			 pg_strcasecmp(prev3_wd, "REPLICA") == 0 &&
+			 pg_strcasecmp(prev2_wd, "IDENTITY") == 0 &&
+			 pg_strcasecmp(prev_wd, "USING") == 0)
+	{
+		COMPLETE_WITH_CONST("INDEX");
+	}
+	else if (pg_strcasecmp(prev4_wd, "TABLE") == 0 &&
+			 pg_strcasecmp(prev2_wd, "REPLICA") == 0 &&
+			 pg_strcasecmp(prev_wd, "IDENTITY") == 0)
+	{
+		static const char *const list_REPLICAID[] =
+		{"FULL", "NOTHING", "DEFAULT", "USING", NULL};
+
+		COMPLETE_WITH_LIST(list_REPLICAID);
+	}
+	else if (pg_strcasecmp(prev3_wd, "TABLE") == 0 &&
+			 pg_strcasecmp(prev_wd, "REPLICA") == 0)
+	{
+		COMPLETE_WITH_CONST("IDENTITY");
+	}
 
 	/* ALTER TABLESPACE <foo> with RENAME TO, OWNER TO, SET, RESET */
 	else if (pg_strcasecmp(prev3_wd, "ALTER") == 0 &&

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201310271
+#define CATALOG_VERSION_NO	201311081
 
 #endif

src/include/catalog/pg_class.h

@@ -66,6 +66,7 @@ CATALOG(pg_class,1259) BKI_BOOTSTRAP BKI_ROWTYPE_OID(83) BKI_SCHEMA_MACRO
 	bool		relhastriggers; /* has (or has had) any TRIGGERs */
 	bool		relhassubclass; /* has (or has had) derived classes */
 	bool		relispopulated; /* matview currently holds query results */
+	char		relreplident;	/* see REPLICA_IDENTITY_xxx constants  */
 	TransactionId relfrozenxid; /* all Xids < this are frozen in this rel */
 	TransactionId relminmxid;	/* all multixacts in this rel are >= this.
 								 * this is really a MultiXactId */
@@ -93,7 +94,7 @@ typedef FormData_pg_class *Form_pg_class;
  * ----------------
  */
 
-#define Natts_pg_class					28
+#define Natts_pg_class					29
 #define Anum_pg_class_relname			1
 #define Anum_pg_class_relnamespace		2
 #define Anum_pg_class_reltype			3
@@ -118,10 +119,11 @@ typedef FormData_pg_class *Form_pg_class;
 #define Anum_pg_class_relhastriggers	22
 #define Anum_pg_class_relhassubclass	23
 #define Anum_pg_class_relispopulated	24
-#define Anum_pg_class_relfrozenxid		25
-#define Anum_pg_class_relminmxid		26
-#define Anum_pg_class_relacl			27
-#define Anum_pg_class_reloptions		28
+#define Anum_pg_class_relreplident		25
+#define Anum_pg_class_relfrozenxid		26
+#define Anum_pg_class_relminmxid		27
+#define Anum_pg_class_relacl			28
+#define Anum_pg_class_reloptions		29
 
 /* ----------------
  *		initial contents of pg_class
@@ -136,13 +138,13 @@ typedef FormData_pg_class *Form_pg_class;
  * Note: "3" in the relfrozenxid column stands for FirstNormalTransactionId;
  * similarly, "1" in relminmxid stands for FirstMultiXactId
  */
-DATA(insert OID = 1247 (  pg_type		PGNSP 71 0 PGUID 0 0 0 0 0 0 0 f f p r 30 0 t f f f f t 3 1 _null_ _null_ ));
+DATA(insert OID = 1247 (  pg_type		PGNSP 71 0 PGUID 0 0 0 0 0 0 0 f f p r 30 0 t f f f f t n 3 1 _null_ _null_ ));
 DESCR("");
-DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 0 PGUID 0 0 0 0 0 0 0 f f p r 21 0 f f f f f t 3 1 _null_ _null_ ));
+DATA(insert OID = 1249 (  pg_attribute	PGNSP 75 0 PGUID 0 0 0 0 0 0 0 f f p r 21 0 f f f f f t n 3 1 _null_ _null_ ));
 DESCR("");
-DATA(insert OID = 1255 (  pg_proc		PGNSP 81 0 PGUID 0 0 0 0 0 0 0 f f p r 27 0 t f f f f t 3 1 _null_ _null_ ));
+DATA(insert OID = 1255 (  pg_proc		PGNSP 81 0 PGUID 0 0 0 0 0 0 0 f f p r 27 0 t f f f f t n 3 1 _null_ _null_ ));
 DESCR("");
-DATA(insert OID = 1259 (  pg_class		PGNSP 83 0 PGUID 0 0 0 0 0 0 0 f f p r 28 0 t f f f f t 3 1 _null_ _null_ ));
+DATA(insert OID = 1259 (  pg_class		PGNSP 83 0 PGUID 0 0 0 0 0 0 0 f f p r 29 0 t f f f f t n 3 1 _null_ _null_ ));
 DESCR("");
 
 
@@ -159,4 +161,16 @@ DESCR("");
 #define		  RELPERSISTENCE_UNLOGGED	'u'		/* unlogged permanent table */
 #define		  RELPERSISTENCE_TEMP		't'		/* temporary table */
 
+/* default selection for replica identity (primary key or nothing) */
+#define		  REPLICA_IDENTITY_DEFAULT	'd'
+/* no replica identity is logged for this relation */
+#define		  REPLICA_IDENTITY_NOTHING	'n'
+/* all columns are loged as replica identity */
+#define		  REPLICA_IDENTITY_FULL		'f'
+/*
+ * an explicitly chosen candidate key's columns are used as identity;
+ * will still be set if the index has been dropped, in that case it
+ * has the same meaning as 'd'
+ */
+#define		  REPLICA_IDENTITY_INDEX	'i'
 #endif   /* PG_CLASS_H */

src/include/catalog/pg_index.h

@@ -42,6 +42,7 @@ CATALOG(pg_index,2610) BKI_WITHOUT_OIDS BKI_SCHEMA_MACRO
 	bool		indcheckxmin;	/* must we wait for xmin to be old? */
 	bool		indisready;		/* is this index ready for inserts? */
 	bool		indislive;		/* is this index alive at all? */
+	bool		indisreplident;	/* is this index the identity for replication? */
 
 	/* variable-length fields start here, but we allow direct access to indkey */
 	int2vector	indkey;			/* column numbers of indexed cols, or 0 */
@@ -69,7 +70,7 @@ typedef FormData_pg_index *Form_pg_index;
  *		compiler constants for pg_index
  * ----------------
  */
-#define Natts_pg_index					18
+#define Natts_pg_index					19
 #define Anum_pg_index_indexrelid		1
 #define Anum_pg_index_indrelid			2
 #define Anum_pg_index_indnatts			3
@@ -82,12 +83,13 @@ typedef FormData_pg_index *Form_pg_index;
 #define Anum_pg_index_indcheckxmin		10
 #define Anum_pg_index_indisready		11
 #define Anum_pg_index_indislive			12
-#define Anum_pg_index_indkey			13
-#define Anum_pg_index_indcollation		14
-#define Anum_pg_index_indclass			15
-#define Anum_pg_index_indoption			16
-#define Anum_pg_index_indexprs			17
-#define Anum_pg_index_indpred			18
+#define Anum_pg_index_indisreplident	13
+#define Anum_pg_index_indkey			14
+#define Anum_pg_index_indcollation		15
+#define Anum_pg_index_indclass			16
+#define Anum_pg_index_indoption			17
+#define Anum_pg_index_indexprs			18
+#define Anum_pg_index_indpred			19
 
 /*
  * Index AMs that support ordered scans must support these two indoption

src/include/nodes/nodes.h

@@ -362,6 +362,7 @@ typedef enum NodeTag
 	T_CreateEventTrigStmt,
 	T_AlterEventTrigStmt,
 	T_RefreshMatViewStmt,
+	T_ReplicaIdentityStmt,
 
 	/*
 	 * TAGS FOR PARSE TREE NODES (parsenodes.h)

src/include/nodes/parsenodes.h

@@ -1284,9 +1284,17 @@ typedef enum AlterTableType
 	AT_DropInherit,				/* NO INHERIT parent */
 	AT_AddOf,					/* OF <type_name> */
 	AT_DropOf,					/* NOT OF */
+	AT_ReplicaIdentity,			/* REPLICA IDENTITY */
 	AT_GenericOptions			/* OPTIONS (...) */
 } AlterTableType;
 
+typedef struct ReplicaIdentityStmt
+{
+	NodeTag		type;
+	char		identity_type;
+	char	   *name;
+} ReplicaIdentityStmt;
+
 typedef struct AlterTableCmd	/* one subcommand of an ALTER TABLE */
 {
 	NodeTag		type;

src/include/utils/rel.h

@@ -110,6 +110,13 @@ typedef struct RelationData
 	MemoryContext rd_rulescxt;	/* private memory cxt for rd_rules, if any */
 	TriggerDesc *trigdesc;		/* Trigger info, or NULL if rel has none */
 
+	/*
+	 * The index chosen as the relation's replication identity or
+	 * InvalidOid. Only set correctly if RelationGetIndexList has been
+	 * called/rd_indexvalid > 0.
+	 */
+	Oid rd_replidindex;
+
 	/*
 	 * rd_options is set whenever rd_rel is loaded into the relcache entry.
 	 * Note that you can NOT look into rd_rel for this data.  NULL means "use

src/test/regress/expected/replica_identity.out

+CREATE TABLE test_replica_identity (
+       id serial primary key,
+       keya text not null,
+       keyb text not null,
+       nonkey text,
+       CONSTRAINT test_replica_identity_unique_defer UNIQUE (keya, keyb) DEFERRABLE,
+       CONSTRAINT test_replica_identity_unique_nondefer UNIQUE (keya, keyb)
+);
+CREATE TABLE test_replica_identity_othertable (id serial primary key);
+CREATE INDEX test_replica_identity_keyab ON test_replica_identity (keya, keyb);
+CREATE UNIQUE INDEX test_replica_identity_keyab_key ON test_replica_identity (keya, keyb);
+CREATE UNIQUE INDEX test_replica_identity_nonkey ON test_replica_identity (keya, nonkey);
+CREATE INDEX test_replica_identity_hash ON test_replica_identity USING hash (nonkey);
+CREATE UNIQUE INDEX test_replica_identity_expr ON test_replica_identity (keya, keyb, (3));
+CREATE UNIQUE INDEX test_replica_identity_partial ON test_replica_identity (keya, keyb) WHERE keyb != '3';
+-- default is 'd'/DEFAULT for user created tables
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+ relreplident 
+--------------
+ d
+(1 row)
+
+-- but 'none' for system tables
+SELECT relreplident FROM pg_class WHERE oid = 'pg_class'::regclass;
+ relreplident 
+--------------
+ n
+(1 row)
+
+SELECT relreplident FROM pg_class WHERE oid = 'pg_constraint'::regclass;
+ relreplident 
+--------------
+ n
+(1 row)
+
+----
+-- Make sure we detect inelegible indexes
+----
+-- fail, not unique
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_keyab;
+ERROR:  cannot use non-unique index "test_replica_identity_keyab" as replica identity
+-- fail, not a candidate key, nullable column
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_nonkey;
+ERROR:  index "test_replica_identity_nonkey" cannot be used as replica identity because column "nonkey" is nullable
+-- fail, hash indexes cannot do uniqueness
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_hash;
+ERROR:  cannot use non-unique index "test_replica_identity_hash" as replica identity
+-- fail, expression index
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_expr;
+ERROR:  cannot use expression index "test_replica_identity_expr" as replica identity
+-- fail, partial index
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_partial;
+ERROR:  cannot use partial index "test_replica_identity_partial" as replica identity
+-- fail, not our index
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_othertable_pkey;
+ERROR:  "test_replica_identity_othertable_pkey" is not an index for table "test_replica_identity"
+-- fail, deferrable
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_unique_defer;
+ERROR:  cannot use non-immediate index "test_replica_identity_unique_defer" as replica identity
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+ relreplident 
+--------------
+ d
+(1 row)
+
+----
+-- Make sure index cases succeeed
+----
+-- succeed, primary key
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_pkey;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+ relreplident 
+--------------
+ i
+(1 row)
+
+\d test_replica_identity
+                         Table "public.test_replica_identity"
+ Column |  Type   |                             Modifiers                              
+--------+---------+--------------------------------------------------------------------
+ id     | integer | not null default nextval('test_replica_identity_id_seq'::regclass)
+ keya   | text    | not null
+ keyb   | text    | not null
+ nonkey | text    | 
+Indexes:
+    "test_replica_identity_pkey" PRIMARY KEY, btree (id) REPLICA IDENTITY
+    "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
+    "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb)
+    "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
+    "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
+    "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
+    "test_replica_identity_unique_nondefer" UNIQUE CONSTRAINT, btree (keya, keyb)
+    "test_replica_identity_hash" hash (nonkey)
+    "test_replica_identity_keyab" btree (keya, keyb)
+
+-- succeed, nondeferrable unique constraint over nonullable cols
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_unique_nondefer;
+-- succeed unique index over nonnullable cols
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_keyab_key;
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_keyab_key;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+ relreplident 
+--------------
+ i
+(1 row)
+
+\d test_replica_identity
+                         Table "public.test_replica_identity"
+ Column |  Type   |                             Modifiers                              
+--------+---------+--------------------------------------------------------------------
+ id     | integer | not null default nextval('test_replica_identity_id_seq'::regclass)
+ keya   | text    | not null
+ keyb   | text    | not null
+ nonkey | text    | 
+Indexes:
+    "test_replica_identity_pkey" PRIMARY KEY, btree (id)
+    "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
+    "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb) REPLICA IDENTITY
+    "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
+    "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
+    "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
+    "test_replica_identity_unique_nondefer" UNIQUE CONSTRAINT, btree (keya, keyb)
+    "test_replica_identity_hash" hash (nonkey)
+    "test_replica_identity_keyab" btree (keya, keyb)
+
+SELECT count(*) FROM pg_index WHERE indrelid = 'test_replica_identity'::regclass AND indisreplident;
+ count 
+-------
+     1
+(1 row)
+
+----
+-- Make sure non index cases work
+----
+ALTER TABLE test_replica_identity REPLICA IDENTITY DEFAULT;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+ relreplident 
+--------------
+ d
+(1 row)
+
+SELECT count(*) FROM pg_index WHERE indrelid = 'test_replica_identity'::regclass AND indisreplident;
+ count 
+-------
+     0
+(1 row)
+
+ALTER TABLE test_replica_identity REPLICA IDENTITY FULL;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+ relreplident 
+--------------
+ f
+(1 row)
+
+\d test_replica_identity
+                         Table "public.test_replica_identity"
+ Column |  Type   |                             Modifiers                              
+--------+---------+--------------------------------------------------------------------
+ id     | integer | not null default nextval('test_replica_identity_id_seq'::regclass)
+ keya   | text    | not null
+ keyb   | text    | not null
+ nonkey | text    | 
+Indexes:
+    "test_replica_identity_pkey" PRIMARY KEY, btree (id)
+    "test_replica_identity_expr" UNIQUE, btree (keya, keyb, (3))
+    "test_replica_identity_keyab_key" UNIQUE, btree (keya, keyb)
+    "test_replica_identity_nonkey" UNIQUE, btree (keya, nonkey)
+    "test_replica_identity_partial" UNIQUE, btree (keya, keyb) WHERE keyb <> '3'::text
+    "test_replica_identity_unique_defer" UNIQUE CONSTRAINT, btree (keya, keyb) DEFERRABLE
+    "test_replica_identity_unique_nondefer" UNIQUE CONSTRAINT, btree (keya, keyb)
+    "test_replica_identity_hash" hash (nonkey)
+    "test_replica_identity_keyab" btree (keya, keyb)
+Replica Identity: FULL
+
+ALTER TABLE test_replica_identity REPLICA IDENTITY NOTHING;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+ relreplident 
+--------------
+ n
+(1 row)
+
+DROP TABLE test_replica_identity;
+DROP TABLE test_replica_identity_othertable;

src/test/regress/parallel_schedule

@@ -83,7 +83,7 @@ test: select_into select_distinct select_distinct_on select_implicit select_havi
 # ----------
 # Another group of parallel tests
 # ----------
-test: privileges security_label collate matview lock
+test: privileges security_label collate matview lock replica_identity
 
 # ----------
 # Another group of parallel tests

src/test/regress/serial_schedule

@@ -98,6 +98,7 @@ test: security_label
 test: collate
 test: matview
 test: lock
+test: replica_identity
 test: alter_generic
 test: misc
 test: psql

src/test/regress/sql/replica_identity.sql

+CREATE TABLE test_replica_identity (
+       id serial primary key,
+       keya text not null,
+       keyb text not null,
+       nonkey text,
+       CONSTRAINT test_replica_identity_unique_defer UNIQUE (keya, keyb) DEFERRABLE,
+       CONSTRAINT test_replica_identity_unique_nondefer UNIQUE (keya, keyb)
+);
+
+CREATE TABLE test_replica_identity_othertable (id serial primary key);
+
+CREATE INDEX test_replica_identity_keyab ON test_replica_identity (keya, keyb);
+CREATE UNIQUE INDEX test_replica_identity_keyab_key ON test_replica_identity (keya, keyb);
+CREATE UNIQUE INDEX test_replica_identity_nonkey ON test_replica_identity (keya, nonkey);
+CREATE INDEX test_replica_identity_hash ON test_replica_identity USING hash (nonkey);
+CREATE UNIQUE INDEX test_replica_identity_expr ON test_replica_identity (keya, keyb, (3));
+CREATE UNIQUE INDEX test_replica_identity_partial ON test_replica_identity (keya, keyb) WHERE keyb != '3';
+
+-- default is 'd'/DEFAULT for user created tables
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+-- but 'none' for system tables
+SELECT relreplident FROM pg_class WHERE oid = 'pg_class'::regclass;
+SELECT relreplident FROM pg_class WHERE oid = 'pg_constraint'::regclass;
+
+----
+-- Make sure we detect inelegible indexes
+----
+
+-- fail, not unique
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_keyab;
+-- fail, not a candidate key, nullable column
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_nonkey;
+-- fail, hash indexes cannot do uniqueness
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_hash;
+-- fail, expression index
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_expr;
+-- fail, partial index
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_partial;
+-- fail, not our index
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_othertable_pkey;
+-- fail, deferrable
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_unique_defer;
+
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+
+----
+-- Make sure index cases succeeed
+----
+
+-- succeed, primary key
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_pkey;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+\d test_replica_identity
+
+-- succeed, nondeferrable unique constraint over nonullable cols
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_unique_nondefer;
+
+-- succeed unique index over nonnullable cols
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_keyab_key;
+ALTER TABLE test_replica_identity REPLICA IDENTITY USING INDEX test_replica_identity_keyab_key;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+\d test_replica_identity
+SELECT count(*) FROM pg_index WHERE indrelid = 'test_replica_identity'::regclass AND indisreplident;
+
+----
+-- Make sure non index cases work
+----
+ALTER TABLE test_replica_identity REPLICA IDENTITY DEFAULT;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+SELECT count(*) FROM pg_index WHERE indrelid = 'test_replica_identity'::regclass AND indisreplident;
+
+ALTER TABLE test_replica_identity REPLICA IDENTITY FULL;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+\d test_replica_identity
+ALTER TABLE test_replica_identity REPLICA IDENTITY NOTHING;
+SELECT relreplident FROM pg_class WHERE oid = 'test_replica_identity'::regclass;
+
+DROP TABLE test_replica_identity;
+DROP TABLE test_replica_identity_othertable;