Hi all,

Of course, bug fixes always come in after the release is published :-/

At 20:42 26/01/2006, Chris Browne wrote:
>    2. Improved SUBSCRIBE SET performance. Indices are temporarily
>    detached during the COPY statements, and then reattached and
>    reindexed, which, in principle, should mean that subscribing a set
>    should even be a bit faster than restoring from pg_dump (with
>    Slony-I all the indices are regenerated together, so there should
>    be benefits from the data already being in cache).

[...]

>    4. TRUNCATE is used to clear out tables at subscription time, if
>    possible.

There is an issue with these two: if TRUNCATE fails (because there's 
a foreign key referencing that table), then the index creation is not 
deferred (the exception rolls back any changes in prepareTableForCopy).

Proposed fix (put the truncate-else-delete in a nested BEGIN block):

--- src/backend/slony1_funcs.v80.sql.orig       Fri Jan  6 18:07:46 2006
+++ src/backend/slony1_funcs.v80.sql    Fri Jan 27 11:32:13 2006
@@ -47,17 +47,20 @@
         -- ----
         update pg_class set relhasindex = ''f'' where oid = v_tab_oid;

-       -- ----
-       -- Try using truncate to empty the table and fallback to
-       -- delete on error.
-       -- ----
-       execute ''truncate '' || @NAMESPACE at .slon_quote_input(v_tab_fqname);
-       raise notice ''truncate of % succeeded'', v_tab_fqname;
-       return 1;
-       exception when others then
-               raise notice ''truncate of % failed - doing delete'', 
v_tab_fqname;
-               execute ''delete from only '' || 
@NAMESPACE at .slon_quote_input(v_tab_fqname);
-               return 0;
+       begin
+               -- ----
+               -- Try using truncate to empty the table and fallback to
+               -- delete on error.
+               -- ----
+               execute ''truncate '' || 
@NAMESPACE at .slon_quote_input(v_tab_fqname);
+               raise notice ''truncate of % succeeded'', v_tab_fqname;
+               return 1;
+       exception
+               when others then
+                       raise notice ''truncate of % failed - doing 
delete'', v_tab_fqname;
+                       execute ''delete from only '' || 
@NAMESPACE at .slon_quote_input(v_tab_fqname);
+                       return 0;
+       end;
  end;
  ' language plpgsql;

This is against 1.1.5-rc3, but I think it should work against the 
release as well.

Also TRUNCATE is only used for PostgreSQL 8.0+, apparently.

I have another issue at the moment with a supposedly duplicate key in 
the updates just after the copy_set is done, I'll post when I have 
more info (and hopefully a fix).

Jacques.