"Mikito Harakiri" <mikharakiri_at_ywho.com> wrote in message news:csZka.8$PD5.119_at_news.oracle.com...
> "Sybrand Bakker" <gooiditweg_at_nospam.demon.nl> wrote in message
> news:1jk89vo64iubghsbnb6o6aro39l8njo44i_at_4ax.com...
> > Because in PL/SQL blocks the optimizer always goes for ALL_ROWS mode,
> > and first_rows hints are ignored.
>
> Old heuristic-based "first_rows" or new cost-based "first_rows"?
>
> Even if it's true, then it's just an ugly artifact that could be submitted
> as bug. Essentially it is saying that PL/SQL client code is different from
> anything else. As if a user can't open cursor in PL/SQL block and fetch 10
> first rows only.
Actually, what Sybrand probably meant is that the OPTIMIZER_MODE
setting is ignored in PL/SQL and is always assumed ALL_ROWS.
But to my knowledge hints are not ignored, so if you hint your
query with /*+ FIRST_ROWS */, it will be executed in this mode
by both PL/SQL and SQL engines. By the way, this may not apply
to 9i since PL/SQL and SQL use the same engine in 9i.
--
Vladimir Zakharychev (bob@dpsp-yes.com) http://www.dpsp-yes.com
Dynamic PSP(tm) - the first true RAD toolkit for Oracle-based internet applications.
All opinions are mine and do not necessarily go in line with those of my employer.
Received on Thu Apr 10 2003 - 06:22:30 CDT
