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Re: InstantDB: PoolMan and IDB


Well, agree with you: if the ResultSet is closed, the MetaData can't be
considered valid.
But since it seems that PoolMan is one of the favorites Connection Pools, it
could be useful
to find a workaround... but at the PoolMan side!
No other thoughts :)
Thank you!
Massimo


> I'll let you make the judgement as to whether or not this is a poolman
> bug or an idb bug, but here's the scoop.  When poolman opens a result
> set, it first gets the result set from the original statement (the idb
> one).  Then, it keeps a copy of the meta data, but copies all the rows
> of the resultset into it's own data structure.  It then closes the
> resultset.  The problem here is that when idb gets a resultset, it's
> using a temporary table to hold the results, so when it closes it
> actually drops this temporary table.  This clears out all the column
> info.  The idb metadata class uses the temporary table to get all the
> column info, so when you make this call, a NullPointerException occurs.
>
> I'll look at the latest poolman code to see if this problem is fixed.
> We could detach idbResultSetMetaData from the underlying temporary
> table, but to me, if the rs is closed, then there's no reason the
> metadata should be valid.  However, it looks like other drivers aren't
> invalidating their metadata on resultset closure, so this may be
> something we want to fix.
>
> Thoughts?
>
> Thom
>
> Massimo Ferrari wrote:
> >
> > All the files are attached.
> > Thank you
> > Massimo
> >
> > > Can you attach your poolman.props file?
> > >
> > > Thanks,
> > >
> > > Thom
> > >
> > > Massimo Ferrari wrote:
> > > >
> > > > Hi,
> > > > I'm using IDB 3.26 and PoolMan 1.4.1
> > > >
> > > > the following test code causes an error when I try to get the number
of
> > > > columns from the ResultSetMetaData.
> > > > The same code without poolman runs correctly.
> > > > Any idea?
> > > > Thank you in advance
> > > > Massimo
> > >
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