Refuse upgrades from pre-9.0 clusters

Commit 695b4a113ab added a dependency on retrieving oldestxid from
pg_control, which only exists in 9.0 and onwards, but the check for
8.4 as the oldest version was retained. Since there has been few if
any complaints of 8.4 upgrades not working, fix by setting 9.0 as
the oldest version supported rather than resurrecting 8.4 support.

Backpatch to all supported versions.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1973418.1657040382@sss.pgh.pa.us
Backpatch-through: v12

diff --git a/doc/src/sgml/ref/pgupgrade.sgml b/doc/src/sgml/ref/pgupgrade.sgml
index d401053edf3813dddf5edccdf4af1aa2a9fd4df7..8add90e8ed3ba71a001dc16733930eb14f7500b0 100644 (file)
--- a/doc/src/sgml/ref/pgupgrade.sgml
+++ b/doc/src/sgml/ref/pgupgrade.sgml
@@ -67,7 +67,7 @@ PostgreSQL documentation
  </para>
 
   <para>
-   pg_upgrade supports upgrades from 8.4.X and later to the current
+   pg_upgrade supports upgrades from 9.0.X and later to the current
    major release of <productname>PostgreSQL</productname>, including snapshot and beta releases.
   </para>
  </refsect1>

diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index dc060418e507e06db4c4d9a331ebb64b016a1b96..26dae5681a78d117c195e73a35e1a04c634eb10c 100644 (file)
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -316,8 +316,13 @@ check_cluster_versions(void)
     * upgrades
     */
 
-   if (GET_MAJOR_VERSION(old_cluster.major_version) < 804)
-       pg_fatal("This utility can only upgrade from PostgreSQL version 8.4 and later.\n");
+   /*
+    * The minimum version supported when this code shipped in a major version
+    * was 8.4. This has since been raised to 9.0, but the support code for
+    * dealing with 8.4 remains to avoid refactoring in a backbranch.
+    */
+   if (GET_MAJOR_VERSION(old_cluster.major_version) < 900)
+       pg_fatal("This utility can only upgrade from PostgreSQL version 9.0 and later.\n");
 
    /* Only current PG version is supported as a target */
    if (GET_MAJOR_VERSION(new_cluster.major_version) != GET_MAJOR_VERSION(PG_VERSION_NUM))