Il 29/08/2012 18.09, Chris Angelico ha scritto:
> On Thu, Aug 30, 2012 at 1:56 AM, Nicola Cisternino<ncister(at)tiscali(dot)it> wrote:
>> The same query using " .... LIKE<value> ...." is completed in 15 ms while
>> using " .... ILIKE<value> ...." the execution time is 453 ms ....
> Sounds to me like (pun not intended) there's an index that's being
> used in one case and not in the other.
>
> But taking this back a step: Do you really need case-insensitive
> comparisons? They become pretty much impossible once you start looking
> at internationalization. Sure, it's easy in ASCII. You just mask off
> one bit and off you go. But truly case insensitive matching gets
> really hairy. Can you redo things with case sensitive searches,
> possibly with some forcing of case in simple situations? For instance,
> you accept a name prefix from the user, look at it and find that it's
> all ASCII; lower-case it, then upper-case the first letter, then add a
> percent sign, and use a case-sensitive LIKE. That's going to produce
> correct results in most cases, and is way faster than truly case
> insensitive searching.
>
> ChrisA
>
>
Yes I need case-insensitive comparision and the best way to (optionally)
obtain it is without alter all application queries that already works
with other DB engine (!!)
My simply questions are:
1) Can be a custom collation a solution for my needs ?
2) How can create a custom collation (... what steps ...) ?
Thanks.