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catversion.h
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1/*-------------------------------------------------------------------------
2 *
3 * catversion.h
4 * "Catalog version number" for PostgreSQL.
5 *
6 * The catalog version number is used to flag incompatible changes in
7 * the PostgreSQL system catalogs. Whenever anyone changes the format of
8 * a system catalog relation, or adds, deletes, or modifies standard
9 * catalog entries in such a way that an updated backend wouldn't work
10 * with an old database (or vice versa), the catalog version number
11 * should be changed. The version number stored in pg_control by initdb
12 * is checked against the version number compiled into the backend at
13 * startup time, so that a backend can refuse to run in an incompatible
14 * database.
15 *
16 * The point of this feature is to provide a finer grain of compatibility
17 * checking than is possible from looking at the major version number
18 * stored in PG_VERSION. It shouldn't matter to end users, but during
19 * development cycles we usually make quite a few incompatible changes
20 * to the contents of the system catalogs, and we don't want to bump the
21 * major version number for each one. What we can do instead is bump
22 * this internal version number. This should save some grief for
23 * developers who might otherwise waste time tracking down "bugs" that
24 * are really just code-vs-database incompatibilities.
25 *
26 * The rule for developers is: if you commit a change that requires
27 * an initdb, you should update the catalog version number (as well as
28 * notifying the pgsql-hackers mailing list, which has been the
29 * informal practice for a long time).
30 *
31 * The catalog version number is placed here since modifying files in
32 * include/catalog is the most common kind of initdb-forcing change.
33 * But it could be used to protect any kind of incompatible change in
34 * database contents or layout, such as altering tuple headers.
35 * Another common reason for a catversion update is a change in parsetree
36 * external representation, since serialized parsetrees appear in stored
37 * rules and new-style SQL functions. Almost any change in primnodes.h or
38 * parsenodes.h will warrant a catversion update.
39 *
40 *
41 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
42 * Portions Copyright (c) 1994, Regents of the University of California
43 *
44 * src/include/catalog/catversion.h
45 *
46 *-------------------------------------------------------------------------
47 */
48#ifndef CATVERSION_H
49#define CATVERSION_H
50
51/*
52 * We could use anything we wanted for version numbers, but I recommend
53 * following the "YYYYMMDDN" style often used for DNS zone serial numbers.
54 * YYYYMMDD are the date of the change, and N is the number of the change
55 * on that day. (Hopefully we'll never commit ten independent sets of
56 * catalog changes on the same day...)
57 */
58
59/* yyyymmddN */
60#define CATALOG_VERSION_NO 202505071
61
62#endif