Update copyright for 2021

Backpatch-through: 9.5

src/backend/optimizer/path/allpaths.c

@@ -3,7 +3,7 @@
  * allpaths.c
  *	  Routines to find possible search paths for processing a query
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/optimizer/path/clausesel.c

@@ -3,7 +3,7 @@
  * clausesel.c
  *	  Routines to compute clause selectivities
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/optimizer/path/costsize.c

@@ -60,7 +60,7 @@
  * values.
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/optimizer/path/equivclass.c

@@ -6,7 +6,7 @@
  * See src/backend/optimizer/README for discussion of EquivalenceClasses.
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/optimizer/path/indxpath.c

@@ -4,7 +4,7 @@
  *	  Routines to determine which indexes are usable for scanning a
  *	  given relation, and create Paths accordingly.
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/optimizer/path/joinpath.c

@@ -3,7 +3,7 @@
  * joinpath.c
  *	  Routines to find all possible paths for processing a set of joins
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/optimizer/path/joinrels.c

@@ -3,7 +3,7 @@
  * joinrels.c
  *	  Routines to determine which relations should be joined
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *

src/backend/optimizer/path/pathkeys.c

@@ -7,7 +7,7 @@
  * the nature and use of path keys.
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION

src/backend/optimizer/path/tidpath.c

@@ -24,7 +24,7 @@
  * representation all the way through to execution.
  *
  *
- * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *