text: /*-------------------------------------------------------------------------
   *
   * catversion.h
   *	  "Catalog version number" for PostgreSQL.
   *
   * The catalog version number is used to flag incompatible changes in
   * the PostgreSQL system catalogs.  Whenever anyone changes the format of
   * a system catalog relation, or adds, deletes, or modifies standard
   * catalog entries in such a way that an updated backend wouldn't work
   * with an old database (or vice versa), the catalog version number
   * should be changed.  The version number stored in pg_control by initdb
   * is checked against the version number compiled into the backend at
   * startup time, so that a backend can refuse to run in an incompatible
   * database.
   *
   * The point of this feature is to provide a finer grain of compatibility
   * checking than is possible from looking at the major version number
   * stored in PG_VERSION.  It shouldn't matter to end users, but during
   * development cycles we usually make quite a few incompatible changes
   * to the contents of the system catalogs, and we don't want to bump the
   * major version number for each one.  What we can do instead is bump
   * this internal version number.  This should save some grief for
   * developers who might otherwise waste time tracking down "bugs" that
   * are really just code-vs-database incompatibilities.
   *
   * The rule for developers is: if you commit a change that requires
   * an initdb, you should update the catalog version number (as well as
   * notifying the pgsql-hackers mailing list, which has been the
   * informal practice for a long time).
   *
   * The catalog version number is placed here since modifying files in
   * include/catalog is the most common kind of initdb-forcing change.
   * But it could be used to protect any kind of incompatible change in
   * database contents or layout, such as altering tuple headers.
   *
   *
   * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
   * Portions Copyright (c) 1994, Regents of the University of California
   *
   * src/include/catalog/catversion.h
   *
   *-------------------------------------------------------------------------
   */
  #ifndef CATVERSION_H
  #define CATVERSION_H
  
  /*
   * We could use anything we wanted for version numbers, but I recommend
   * following the "YYYYMMDDN" style often used for DNS zone serial numbers.
   * YYYYMMDD are the date of the change, and N is the number of the change
   * on that day.  (Hopefully we'll never commit ten independent sets of
   * catalog changes on the same day...)
   */
  
  /*							yyyymmddN */
  #define CATALOG_VERSION_NO	202107151
  
  #endif
  