Throw error sooner for unlogged GiST indexes.

Throwing an error only after we've built the main index fork is pretty
unfriendly when the table already contains data.  Per gripe from Jay
Levitt.

diff --git a/src/backend/access/gist/gistbuild.c b/src/backend/access/gist/gistbuild.c
index 021a8dcf44b98539940ed08a0d4a9c41bce16c2d..3dc3e96df4d9c13833c8b1dc15a5a3e06f5078fc 100644 (file)
--- a/src/backend/access/gist/gistbuild.c
+++ b/src/backend/access/gist/gistbuild.c
@@ -144,6 +144,16 @@ gistbuild(PG_FUNCTION_ARGS)
        elog(ERROR, "index \"%s\" already contains data",
             RelationGetRelationName(index));
 
+   /*
+    * We can't yet handle unlogged GiST indexes, because we depend on LSNs.
+    * This is duplicative of an error in gistbuildempty, but we want to check
+    * here so as to throw error before doing all the index-build work.
+    */
+   if (heap->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED)
+       ereport(ERROR,
+               (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                errmsg("unlogged GiST indexes are not supported")));
+
    /* no locking is needed */
    buildstate.giststate = initGISTstate(index);