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From Mamta Satoor <ma...@Remulak.Net>
Subject Re: [jira] Commented: (DERBY-66) Derby supports open cursor across commits and hence DatabaseMetaData.supportsOpenCursorsAcrossCommit return true.
Date Fri, 12 Nov 2004 20:44:43 GMT
That is a good question.

I looked up in the bok JDBC API Tutorial and Reference, Third Edition.
On page 44 and it says following
"Result Sets and Cursors
The rows that satisfy the conditions of a query are called the
result set. A user can access the data in a result set one row
at a time, and a cursor provides the means to do that. A cursor
can be thought of as a pointer into a file that contains the rows
of the result set, and that pointer has the ability to keep track
of which row is currently being accessed........
Most DBMSs create a cursor automatically when a result
set in generated".

So, it looks there a fine line between a cursor and resultset.
Based on the information from the book, does it mean there
is 1 to 1 relationship between cursor and resultset and hence
if the database supports holdable resultset then that also
means cursors are held over commit?

Any comments/feedback from the Derby community on this.
Mamta


"Jon Craven (JIRA)" wrote:

>      [ http://nagoya.apache.org/jira/browse/DERBY-66?page=comments#action_55394 ]
>
> Jon Craven commented on DERBY-66:
> ---------------------------------
>
> What's the difference between open cursors across commits and holding cursors across
commit?  Derby clearly supports the latter, supportsResultSetHoldability() returns true and
HOLD_CURSORS_OVER_COMMIT is the default holdability.
>
> > Derby supports open cursor across commits and hence DatabaseMetaData.supportsOpenCursorsAcrossCommit
return true.
> > -----------------------------------------------------------------------------------------------------------------
> >
> >          Key: DERBY-66
> >          URL: http://nagoya.apache.org/jira/browse/DERBY-66
> >      Project: Derby
> >         Type: Bug
> >   Components: JDBC
> >     Versions: 10.0.2.0
> >     Reporter: Mamta A. Satoor
> >     Priority: Minor
>
> >
> > Derby returns false for DatabaseMetaData.supportsOpenCursorsAcrossCommit. But that
seems incorrect because Derby does support open cursor across commits and hence DatabaseMetaData.supportsOpenCursorsAcrossCommit
return true.
>
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