Hi Martin,

> "select first 1 id from table order by id descending" (in order to
> select the last record) is *WAY* slower than "select first 1 id from
> table order by id ascending" (in order to select the first)

as you ORDER BY ID *DESCENDING* the optimizer looks for a DESCENDING
index and doesn't find one ...

try

CREATE DESCENDING INDEX indexname ON table (ID);

and see if this improves the situation :-)


Best Regards

Stefan


--
Stefan Heymann
www.destructor.de/firebird