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From Oystein Grovlen - Sun Norway <Oystein.Grov...@Sun.COM>
Subject Re: Using/Adressing a "row number" in a SELECT query
Date Fri, 17 Feb 2006 15:15:08 GMT
Sylvain RICHET wrote:
> OK Bernt, thanks.
> 
> I have already tested these methods.

It seems like these methods does not satisfy your needs.  Can you tell 
us why?

> Maybe anything to add about the lack of "row number" pointer at SQL 
> level ? ...
> 

I am bit confused about what you need a "row number" pointer for. 
Oracle's RowID and MySql's LIMIT seems like quite different features.

--
Øystein


> 
> 
> On 2/17/06, *Bernt M. Johnsen* <Bernt.Johnsen@sun.com 
> <mailto:Bernt.Johnsen@sun.com>> wrote:
> 
>      >>>>>>>>>>>> Sylvain RICHET wrote (2006-02-17
11:55:37):
>      > Thanks Legolas,
>      >
>      > ... but limiting the fetch size by JDBC API supported methods
>     (setFetchSize)
>      > implies that i have already loaded ALL records from database, no ?
> 
>     setFetchSize is an optimization hint to the driver/database and will
>     not affect the result.
> 
>     setMaxRows will limit the number of rows in the resulting
>     resultset. And any decent JDBC-driver will limit the number of rows
>     "loaded" from the database (in client/server mode, that is).
> 
>      >
>      > However, the datas persisted in my DERBY database concern
>     logging. It means
>      > that i would have to get thousands of records.
>      >
>      > On 2/17/06, Legolas Woodland <legolas.w@gmail.com
>     <mailto:legolas.w@gmail.com>> wrote:
>      > >
>      > > Sylvain RICHET wrote:
>      > >
>      > > Hi everyone,
>      > >
>      > > In a selection statement, i would like to get blocks of records.
>      > > Thus, i need to filter records by a "row number", directly at
>     the SELECT
>      > > level.
>      > >
>      > > It seems that the way to address a row number is not (SQL)
>     standard.
>      > > (different "proprietary" implementations)
>      > >
>      > > In Oracle, there is the "rowid".
>      > > In MySQL, the "LIMIT" clause can do it.
>      > > In SQL Server, i think there is the "ROW_NUMBER() OVER..."
>      > > In DB2 (on AS/400) , there is the "RRN" (Relative Record Number)...
>      > >
>      > > What about Derby database ?
>      > > How is it implemented on this server ?
>      > >
>      > > I know i could use
>      > >
>      > > Thanks in advance.
>      > >
>      > > Derby sql does not has any facilities for limiting number of
>     rows in
>      > > select statement.
>      > > you can just limit the fetch size in JDBC resultSets.
>      > >
>      > >
> 
>     --
>     Bernt Marius Johnsen, Database Technology Group,
>     Staff Engineer, Technical Lead Derby/Java DB
>     Sun Microsystems, Trondheim, Norway
> 
> 
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> 
> 


-- 
Øystein Grøvlen, Senior Staff Engineer
Sun Microsystems, Database Technology Group
Trondheim, Norway

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