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

6 files changed, 49 insertions, 17 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 4aa0edf399..4108f6c16c 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201310271
+#define CATALOG_VERSION_NO	201311081
 
 #endif
diff --git a/src/include/catalog/pg_class.h b/src/include/catalog/pg_class.h
index 49c4f6f136..a1fee11fe6 100644
--- a/src/include/catalog/pg_class.h
+++ b/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 */
diff --git a/src/include/catalog/pg_index.h b/src/include/catalog/pg_index.h
index 8d1d415939..b31d9d7643 100644
--- a/src/include/catalog/pg_index.h
+++ b/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
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 78368c63c1..fc6b1d7dbd 100644
--- a/src/include/nodes/nodes.h
+++ b/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)
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index e5235cbf40..952fbb30dd 100644
--- a/src/include/nodes/parsenodes.h
+++ b/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;
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index 589c9a81b6..21d5871454 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -111,6 +111,13 @@ typedef struct RelationData
 	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
 	 * defaults".