On 4 February 2011 04:46, Josh Berkus <josh@agliodbs.com> wrote: > "Optimizer hints are used to work around problems in the optimizer and > introduce upgrade and maintenance issues. We would rather have the > problems reported and fixed. We have discussed a more sophisticated > system of per-class cost adjustment instead, but a specification remains > to be developed."
I have no clue about how hints works in Oracle ... I've never been working "enterprise level" on anything else than Postgres. Anyway, today I just came over an interesting problem in our production database today - and I think it would be a benefit to be able to explicitly tell the planner what index to use (the dev team is adding redundant attributes and more indexes to solve the problem - which worries me, because we will run into serious problems as soon as there won't be enough memory for all the frequently-used indexes).
We have users and transactions, and we have transaction types. The transaction table is huge. The users are able to interactively check their transaction listings online, and they have some simple filter options available as well. Slightly simplified, the queries done looks like this:
select * from account_transaction where account_id=? order by created desc limit 25;
select * from account_transaction where trans_type_id in ( ... long, hard-coded list ...) and account_id=? order by created desc limit 25;