Database-level collation version tracking

This adds to database objects the same version tracking that collation
objects have.  There is a new pg_database column datcollversion that
stores the version, a new function
pg_database_collation_actual_version() to get the version from the
operating system, and a new subcommand ALTER DATABASE ... REFRESH
COLLATION VERSION.

This was not originally added together with pg_collation.collversion,
since originally version tracking was only supported for ICU, and ICU
on a database-level is not currently supported.  But we now have
version tracking for glibc (since PG13), FreeBSD (since PG14), and
Windows (since PG13), so this is useful to have now.

Reviewed-by: Julien Rouhaud <rjuju123@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/f0ff3190-29a3-5b39-a179-fa32eee57db6%40enterprisedb.com

6 files changed, 17 insertions, 1 deletions

diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 08f9b984d7f..b940a0cf0cb 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202202101
+#define CATALOG_VERSION_NO	202202141
 
 #endif
diff --git a/src/include/catalog/pg_database.h b/src/include/catalog/pg_database.h
index 90b43a4ecc9..76adbd4aade 100644
--- a/src/include/catalog/pg_database.h
+++ b/src/include/catalog/pg_database.h
@@ -65,6 +65,9 @@ CATALOG(pg_database,1262,DatabaseRelationId) BKI_SHARED_RELATION BKI_ROWTYPE_OID
 	/* LC_CTYPE setting */
 	text		datctype BKI_FORCE_NOT_NULL;
 
+	/* provider-dependent version of collation data */
+	text		datcollversion BKI_DEFAULT(_null_);
+
 	/* access permissions */
 	aclitem		datacl[1];
 #endif
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 62f36daa981..7f1ee97f55c 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -11627,6 +11627,11 @@
   proname => 'pg_collation_actual_version', procost => '100',
   provolatile => 'v', prorettype => 'text', proargtypes => 'oid',
   prosrc => 'pg_collation_actual_version' },
+{ oid => '9167',
+  descr => 'get actual version of database collation from operating system',
+  proname => 'pg_database_collation_actual_version', procost => '100',
+  provolatile => 'v', prorettype => 'text', proargtypes => 'oid',
+  prosrc => 'pg_database_collation_actual_version' },
 
 # system management/monitoring related functions
 { oid => '3353', descr => 'list files in the log directory',
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index b1e8b5eb969..c4947fa71f7 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -24,6 +24,7 @@ extern void dropdb(const char *dbname, bool missing_ok, bool force);
 extern void DropDatabase(ParseState *pstate, DropdbStmt *stmt);
 extern ObjectAddress RenameDatabase(const char *oldname, const char *newname);
 extern Oid	AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel);
+extern ObjectAddress AlterDatabaseRefreshColl(AlterDatabaseRefreshCollStmt *stmt);
 extern Oid	AlterDatabaseSet(AlterDatabaseSetStmt *stmt);
 extern ObjectAddress AlterDatabaseOwner(const char *dbname, Oid newOwnerId);
 
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index da35f2c2722..5d075f0c346 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -370,6 +370,7 @@ typedef enum NodeTag
 	T_CheckPointStmt,
 	T_CreateSchemaStmt,
 	T_AlterDatabaseStmt,
+	T_AlterDatabaseRefreshCollStmt,
 	T_AlterDatabaseSetStmt,
 	T_AlterRoleSetStmt,
 	T_CreateConversionStmt,
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 37fcc4c9b5a..34218b718c1 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3308,6 +3308,12 @@ typedef struct AlterDatabaseStmt
 	List	   *options;		/* List of DefElem nodes */
 } AlterDatabaseStmt;
 
+typedef struct AlterDatabaseRefreshCollStmt
+{
+	NodeTag		type;
+	char	   *dbname;
+} AlterDatabaseRefreshCollStmt;
+
 typedef struct AlterDatabaseSetStmt
 {
 	NodeTag		type;