Adjust pg_dumpall so that it emits ENCODING, LC_COLLATE, and LC_CTYPE options

in its CREATE DATABASE commands only for databases that have settings
different from the installation defaults.  This is a low-tech method of
avoiding unnecessary platform dependencies in dump files.  Eventually we ought
to have a platform-independent way of specifying LC_COLLATE and LC_CTYPE, but
that's not going to happen for 8.4, and this patch at least avoids the issue
for people who aren't setting up per-database locales.  ENCODING doesn't have
the platform dependency problem, but it seems consistent to make it act the
same as the locale settings.

diff --git a/src/bin/pg_dump/pg_dumpall.c b/src/bin/pg_dump/pg_dumpall.c
index c43e905f087cd0b39aa7678776105c12c3d1f43a..f1eebc6074d218689577ec6b9de084f642037667 100644 (file)
--- a/src/bin/pg_dump/pg_dumpall.c
+++ b/src/bin/pg_dump/pg_dumpall.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *
- * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dumpall.c,v 1.124 2009/04/11 20:23:05 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_dump/pg_dumpall.c,v 1.125 2009/05/10 02:51:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1076,11 +1076,59 @@ static void
 dumpCreateDB(PGconn *conn)
 {
        PQExpBuffer buf = createPQExpBuffer();
+       char       *default_encoding = NULL;
+       char       *default_collate = NULL;
+       char       *default_ctype = NULL;
        PGresult   *res;
        int                     i;
 
        fprintf(OPF, "--\n-- Database creation\n--\n\n");
 
+       /*
+        * First, get the installation's default encoding and locale information.
+        * We will dump encoding and locale specifications in the CREATE DATABASE
+        * commands for just those databases with values different from defaults.
+        *
+        * We consider template0's encoding and locale (or, pre-7.1, template1's)
+        * to define the installation default.  Pre-8.4 installations do not
+        * have per-database locale settings; for them, every database must
+        * necessarily be using the installation default, so there's no need to
+        * do anything (which is good, since in very old versions there is no
+        * good way to find out what the installation locale is anyway...)
+        */
+       if (server_version >= 80400)
+               res = executeQuery(conn,
+                                                  "SELECT pg_encoding_to_char(encoding), "
+                                                  "datcollate, datctype "
+                                                  "FROM pg_database "
+                                                  "WHERE datname = 'template0'");
+       else if (server_version >= 70100)
+               res = executeQuery(conn,
+                                                  "SELECT pg_encoding_to_char(encoding), "
+                                                  "null::text AS datcollate, null::text AS datctype "
+                                                  "FROM pg_database "
+                                                  "WHERE datname = 'template0'");
+       else
+               res = executeQuery(conn,
+                                                  "SELECT pg_encoding_to_char(encoding), "
+                                                  "null::text AS datcollate, null::text AS datctype "
+                                                  "FROM pg_database "
+                                                  "WHERE datname = 'template1'");
+
+       /* If for some reason the template DB isn't there, treat as unknown */
+       if (PQntuples(res) > 0)
+       {
+               if (!PQgetisnull(res, 0, 0))
+                       default_encoding = strdup(PQgetvalue(res, 0, 0));
+               if (!PQgetisnull(res, 0, 1))
+                       default_collate = strdup(PQgetvalue(res, 0, 1));
+               if (!PQgetisnull(res, 0, 2))
+                       default_ctype = strdup(PQgetvalue(res, 0, 2));
+       }
+
+       PQclear(res);
+
+       /* Now collect all the information about databases to dump */
        if (server_version >= 80400)
                res = executeQuery(conn,
                                                   "SELECT datname, "
@@ -1184,16 +1232,19 @@ dumpCreateDB(PGconn *conn)
                        if (strlen(dbowner) != 0)
                                appendPQExpBuffer(buf, " OWNER = %s", fmtId(dbowner));
 
-                       appendPQExpBuffer(buf, " ENCODING = ");
-                       appendStringLiteralConn(buf, dbencoding, conn);
+                       if (default_encoding && strcmp(dbencoding, default_encoding) != 0)
+                       {
+                               appendPQExpBuffer(buf, " ENCODING = ");
+                               appendStringLiteralConn(buf, dbencoding, conn);
+                       }
 
-                       if (strlen(dbcollate) != 0)
+                       if (default_collate && strcmp(dbcollate, default_collate) != 0)
                        {
                                appendPQExpBuffer(buf, " LC_COLLATE = ");
                                appendStringLiteralConn(buf, dbcollate, conn);
                        }
 
-                       if (strlen(dbctype) != 0)
+                       if (default_ctype && strcmp(dbctype, default_ctype) != 0)
                        {
                                appendPQExpBuffer(buf, " LC_CTYPE = ");
                                appendStringLiteralConn(buf, dbctype, conn);
@@ -1219,18 +1270,18 @@ dumpCreateDB(PGconn *conn)
 
                        if (strcmp(dbistemplate, "t") == 0)
                        {
-                               appendPQExpBuffer(buf, "UPDATE pg_database SET datistemplate = 't' WHERE datname = ");
+                               appendPQExpBuffer(buf, "UPDATE pg_catalog.pg_database SET datistemplate = 't' WHERE datname = ");
                                appendStringLiteralConn(buf, dbname, conn);
                                appendPQExpBuffer(buf, ";\n");
                        }
 
                        if (binary_upgrade)
                        {
-                               appendPQExpBuffer(buf, "\n-- For binary upgrade, set datfrozenxid.\n");
-                               appendPQExpBuffer(buf, "UPDATE pg_database\n"
-                                                                        "SET datfrozenxid = '%u'\n"
-                                                                        "WHERE datname = ",
-                                                                        dbfrozenxid);
+                               appendPQExpBuffer(buf, "-- For binary upgrade, set datfrozenxid.\n");
+                               appendPQExpBuffer(buf, "UPDATE pg_catalog.pg_database "
+                                                                 "SET datfrozenxid = '%u' "
+                                                                 "WHERE datname = ",
+                                                                 dbfrozenxid);
                                appendStringLiteralConn(buf, dbname, conn);
                                appendPQExpBuffer(buf, ";\n");
                        }