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Re: unicode searchstring, index not used.

From: Joseph Weinstein <joe.remove_this_at_bea.com.remove_this>
Date: Tue, 08 Jul 2003 12:22:40 -0700
Message-ID: <3F0B1A00.13F3FED0@bea.com.remove_this>

ben brugman wrote:

> More verbose.
> J2ee works with Unicode (all over the place).
> Our existing database does not need Unicode, so
> all character columns are implemented as varchar2.
>
> When a search is done from the code, it is send to
> the database as a Unicode search. So something like
>
> select name, number from members where name = n'WIL';
>
> (The n indicating that it is a Unicode string, this is done
> with a JDBC interface (I think), it is not sent as a string but
> as a query with parameters, but the parameter still being unicode).
>

Whose JDBC driver are you using? Most drivers that implement this sort of thing, also have an option to stop prepending the "n'" for this very reason.
Joe Weinstein at BEA

>
> Now if we use a table were name is implemented as Unicode,
> the search will use the index.
>
> If we use our existing table, the search does not use the index.
>
> Problem is that, in J2ee the use of Unicode is general, and as
> far as I know can not be switched of. To my knowledge it can
> not be converted to a 8 bit character set either.
> The used characters all fit in the 8 bit character set, our organisation
> does not use any character outside this set so we do not need Unicode.
>
> Java is the new coding technique in our organisation, most applications
> are in Delphi up to now. I think it would be rediculous that because of
> a change to a new 'coding environment' (read Java) the existing database
> structure can not be used anymore. (That to keep indexes working on should
> implement text fields as a Unicode field).
>
> My question was kept short, hoping that somebody would recognise
> the problem without deterring them from reading the message.
>
> ben brugman.
>
> Sybrand Bakker <gooiditweg_at_sybrandb.demon.nl> schreef in berichtnieuws
> q60mgvos3urmdsg52bau6igmh2h3aatq1r_at_4ax.com...
> > On Tue, 8 Jul 2003 16:44:57 +0200, "ben brugman" <ben_at_niethier.nl>
> > wrote:
> >
> > >Application is J2ee,
> > >The searchstring is supplied in unicode.
> > >Column is varchar and indexed.
> > >The index is not used.
> > >
> > >How to aliviate this ?
> > >
> > >ben brugman
> > >
> >
> >
> > First of all by refrain from posting riddle and quiz questions without
> > prize
> >
> >
> > Sybrand Bakker, Senior Oracle DBA
> >
> > To reply remove -verwijderdit from my e-mail address
Received on Tue Jul 08 2003 - 14:22:40 CDT

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