Indexes with INCLUDE columns and their support in B-tree

This patch introduces INCLUDE clause to index definition.  This clause
specifies a list of columns which will be included as a non-key part in
the index.  The INCLUDE columns exist solely to allow more queries to
benefit from index-only scans.  Also, such columns don't need to have
appropriate operator classes.  Expressions are not supported as INCLUDE
columns since they cannot be used in index-only scans.

Index access methods supporting INCLUDE are indicated by amcaninclude flag
in IndexAmRoutine.  For now, only B-tree indexes support INCLUDE clause.

In B-tree indexes INCLUDE columns are truncated from pivot index tuples
(tuples located in non-leaf pages and high keys).  Therefore, B-tree indexes
now might have variable number of attributes.  This patch also provides
generic facility to support that: pivot tuples contain number of their
attributes in t_tid.ip_posid.  Free 13th bit of t_info is used for indicating
that.  This facility will simplify further support of index suffix truncation.
The changes of above are backward-compatible, pg_upgrade doesn't need special
handling of B-tree indexes for that.

Bump catalog version

Author: Anastasia Lubennikova with contribition by Alexander Korotkov and me
Reviewed by: Peter Geoghegan, Tomas Vondra, Antonin Houska, Jeff Janes,
			 David Rowley, Alexander Korotkov
Discussion: https://www.postgresql.org/message-id/flat/56168952.4010101@postgrespro.ru

3 files changed, 8 insertions, 0 deletions

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 9287baaedc0..d11a6a82f63 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2889,6 +2889,7 @@ _copyConstraint(const Constraint *from)
 	COPY_STRING_FIELD(cooked_expr);
 	COPY_SCALAR_FIELD(generated_when);
 	COPY_NODE_FIELD(keys);
+	COPY_NODE_FIELD(including);
 	COPY_NODE_FIELD(exclusions);
 	COPY_NODE_FIELD(options);
 	COPY_STRING_FIELD(indexname);
@@ -3464,6 +3465,7 @@ _copyIndexStmt(const IndexStmt *from)
 	COPY_STRING_FIELD(accessMethod);
 	COPY_STRING_FIELD(tableSpace);
 	COPY_NODE_FIELD(indexParams);
+	COPY_NODE_FIELD(indexIncludingParams);
 	COPY_NODE_FIELD(options);
 	COPY_NODE_FIELD(whereClause);
 	COPY_NODE_FIELD(excludeOpNames);
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index d758515cfd1..39946959afd 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1368,6 +1368,7 @@ _equalIndexStmt(const IndexStmt *a, const IndexStmt *b)
 	COMPARE_STRING_FIELD(accessMethod);
 	COMPARE_STRING_FIELD(tableSpace);
 	COMPARE_NODE_FIELD(indexParams);
+	COMPARE_NODE_FIELD(indexIncludingParams);
 	COMPARE_NODE_FIELD(options);
 	COMPARE_NODE_FIELD(whereClause);
 	COMPARE_NODE_FIELD(excludeOpNames);
@@ -2620,6 +2621,7 @@ _equalConstraint(const Constraint *a, const Constraint *b)
 	COMPARE_STRING_FIELD(cooked_expr);
 	COMPARE_SCALAR_FIELD(generated_when);
 	COMPARE_NODE_FIELD(keys);
+	COMPARE_NODE_FIELD(including);
 	COMPARE_NODE_FIELD(exclusions);
 	COMPARE_NODE_FIELD(options);
 	COMPARE_STRING_FIELD(indexname);
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 03a91c3352d..26c621c941c 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2707,6 +2707,7 @@ _outIndexStmt(StringInfo str, const IndexStmt *node)
 	WRITE_STRING_FIELD(accessMethod);
 	WRITE_STRING_FIELD(tableSpace);
 	WRITE_NODE_FIELD(indexParams);
+	WRITE_NODE_FIELD(indexIncludingParams);
 	WRITE_NODE_FIELD(options);
 	WRITE_NODE_FIELD(whereClause);
 	WRITE_NODE_FIELD(excludeOpNames);
@@ -3535,6 +3536,7 @@ _outConstraint(StringInfo str, const Constraint *node)
 		case CONSTR_PRIMARY:
 			appendStringInfoString(str, "PRIMARY_KEY");
 			WRITE_NODE_FIELD(keys);
+			WRITE_NODE_FIELD(including);
 			WRITE_NODE_FIELD(options);
 			WRITE_STRING_FIELD(indexname);
 			WRITE_STRING_FIELD(indexspace);
@@ -3544,6 +3546,7 @@ _outConstraint(StringInfo str, const Constraint *node)
 		case CONSTR_UNIQUE:
 			appendStringInfoString(str, "UNIQUE");
 			WRITE_NODE_FIELD(keys);
+			WRITE_NODE_FIELD(including);
 			WRITE_NODE_FIELD(options);
 			WRITE_STRING_FIELD(indexname);
 			WRITE_STRING_FIELD(indexspace);
@@ -3553,6 +3556,7 @@ _outConstraint(StringInfo str, const Constraint *node)
 		case CONSTR_EXCLUSION:
 			appendStringInfoString(str, "EXCLUSION");
 			WRITE_NODE_FIELD(exclusions);
+			WRITE_NODE_FIELD(including);
 			WRITE_NODE_FIELD(options);
 			WRITE_STRING_FIELD(indexname);
 			WRITE_STRING_FIELD(indexspace);