For 8.0 servers, get last built-in oid from pg_database

We didn't start ensuring that all built-in objects had OIDs less than
16384 until 8.1, so for 8.0 servers we still need to query the value out
of pg_database.  We need this, in particular, to distinguish which casts
were built-in and which were user-defined.

For HEAD, we only worry about going back to 8.0, for the back-branches,
we also ensure that 7.0-7.4 work.

Discussion: https://www.postgresql.org/message-id/flat/20160504183952.GE10850%40tamriel.snowman.net

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index c5adc9da3883d5f554143dd5d5ea1e3bb12520e8..83e172e7283419b3ddf4a8f9cf3c4fd2d578756a 100644 (file)
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -96,6 +96,12 @@ bool     g_verbose;          /* User wants verbose narration of our
 /* subquery used to convert user ID (eg, datdba) to user name */
 static const char *username_subquery;
 
+/*
+ * For 8.0 and earlier servers, pulled from pg_database, for 8.1+ we use
+ * FirstNormalObjectId - 1.
+ */
+static Oid g_last_builtin_oid; /* value of the last builtin oid */
+
 /* The specified names/patterns should to match at least one entity */
 static int strict_names = 0;
 
@@ -233,6 +239,7 @@ static char *convertRegProcReference(Archive *fout,
                        const char *proc);
 static char *convertOperatorReference(Archive *fout, const char *opr);
 static char *convertTSFunction(Archive *fout, Oid funcOid);
+static Oid findLastBuiltinOid_V71(Archive *fout, const char *);
 static void selectSourceSchema(Archive *fout, const char *schemaName);
 static char *getFormattedTypeName(Archive *fout, Oid oid, OidOptions opts);
 static void getBlobs(Archive *fout);
@@ -684,6 +691,20 @@ main(int argc, char **argv)
        exit_horribly(NULL,
           "Exported snapshots are not supported by this server version.\n");
 
+   /*
+    * Find the last built-in OID, if needed (prior to 8.1)
+    *
+    * With 8.1 and above, we can just use FirstNormalObjectId - 1.
+    */
+   if (fout->remoteVersion < 80100)
+       g_last_builtin_oid = findLastBuiltinOid_V71(fout,
+                                                   PQdb(GetConnection(fout)));
+   else
+       g_last_builtin_oid = FirstNormalObjectId - 1;
+
+   if (g_verbose)
+       write_msg(NULL, "last built-in OID is %u\n", g_last_builtin_oid);
+
    /* Expand schema selection patterns into OID lists */
    if (schema_include_patterns.head != NULL)
    {
@@ -1494,7 +1515,7 @@ selectDumpableCast(CastInfo *cast, Archive *fout)
     * This would be DUMP_COMPONENT_ACL for from-initdb casts, but they do not
     * support ACLs currently.
     */
-   if (cast->dobj.catId.oid < (Oid) FirstNormalObjectId)
+   if (cast->dobj.catId.oid <= (Oid) g_last_builtin_oid)
        cast->dobj.dump = DUMP_COMPONENT_NONE;
    else
        cast->dobj.dump = fout->dopt->include_everything ?
@@ -1526,7 +1547,7 @@ selectDumpableProcLang(ProcLangInfo *plang, Archive *fout)
        plang->dobj.dump = DUMP_COMPONENT_NONE;
    else
    {
-       if (plang->dobj.catId.oid < (Oid) FirstNormalObjectId)
+       if (plang->dobj.catId.oid <= (Oid) g_last_builtin_oid)
            plang->dobj.dump = fout->remoteVersion < 90600 ?
                DUMP_COMPONENT_NONE : DUMP_COMPONENT_ACL;
        else
@@ -1552,7 +1573,7 @@ selectDumpableAccessMethod(AccessMethodInfo *method, Archive *fout)
     * This would be DUMP_COMPONENT_ACL for from-initdb access methods, but
     * they do not support ACLs currently.
     */
-   if (method->dobj.catId.oid < (Oid) FirstNormalObjectId)
+   if (method->dobj.catId.oid <= (Oid) g_last_builtin_oid)
        method->dobj.dump = DUMP_COMPONENT_NONE;
    else
        method->dobj.dump = fout->dopt->include_everything ?
@@ -1577,7 +1598,7 @@ selectDumpableExtension(ExtensionInfo *extinfo, DumpOptions *dopt)
     * change permissions on those objects, if they wish to, and have those
     * changes preserved.
     */
-   if (dopt->binary_upgrade && extinfo->dobj.catId.oid < (Oid) FirstNormalObjectId)
+   if (dopt->binary_upgrade && extinfo->dobj.catId.oid <= (Oid) g_last_builtin_oid)
        extinfo->dobj.dump = extinfo->dobj.dump_contains = DUMP_COMPONENT_ACL;
    else
        extinfo->dobj.dump = extinfo->dobj.dump_contains =
@@ -8820,8 +8841,8 @@ dumpExtension(Archive *fout, ExtensionInfo *extinfo)
        /*
         * We unconditionally create the extension, so we must drop it if it
         * exists.  This could happen if the user deleted 'plpgsql' and then
-        * readded it, causing its oid to be greater than FirstNormalObjectId.
-        * The FirstNormalObjectId test was kept to avoid repeatedly dropping
+        * readded it, causing its oid to be greater than g_last_builtin_oid.
+        * The g_last_builtin_oid test was kept to avoid repeatedly dropping
         * and recreating extensions like 'plpgsql'.
         */
        appendPQExpBuffer(q, "DROP EXTENSION IF EXISTS %s;\n", qextname);
@@ -15324,6 +15345,33 @@ dumpTableConstraintComment(Archive *fout, ConstraintInfo *coninfo)
    destroyPQExpBuffer(labelq);
 }
 
+/*
+ * findLastBuiltinOid_V71 -
+ *
+ * find the last built in oid
+ *
+ * For 7.1 through 8.0, we do this by retrieving datlastsysoid from the
+ * pg_database entry for the current database.
+ */
+static Oid
+findLastBuiltinOid_V71(Archive *fout, const char *dbname)
+{
+   PGresult   *res;
+   Oid         last_oid;
+   PQExpBuffer query = createPQExpBuffer();
+
+   resetPQExpBuffer(query);
+   appendPQExpBufferStr(query, "SELECT datlastsysoid from pg_database where datname = ");
+   appendStringLiteralAH(query, dbname, fout);
+
+   res = ExecuteSqlQueryForSingleRow(fout, query->data);
+   last_oid = atooid(PQgetvalue(res, 0, PQfnumber(res, "datlastsysoid")));
+   PQclear(res);
+   destroyPQExpBuffer(query);
+
+   return last_oid;
+}
+
 /*
  * dumpSequence
  *   write the declaration (not data) of one user-defined sequence