JDBC best practice

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От Dave Held
Тема JDBC best practice
Дата
Msg-id 49E94D0CFCD4DB43AFBA928DDD20C8F90261848E@asg002.asg.local
обсуждение исходный текст
Ответы Re: JDBC best practice  (Kris Jurka <books@ejurka.com>)
Список pgsql-performance
I'm using a Postgres table as the data source for a JTable
in a Java app.  As a first approximation, I'm implementing
AbstractTableModel.getValueAt() like so:

    public Object getValueAt(int row, int col)
    {
        try
        {
            rs_.absolute(row + 1);
            return rs_.getObject(col + 1);
        }
        catch (Exception e)
        {
            ...
        }
        return null;
    }

Where rs_ is a RecordSet object.  What I'm wondering is
whether it's better to call absolute() or relative() or
next()/previous().  If absolute() is the slowest call,
then I can cache the last row fetched and move relative
to that.

My suspicion is that next()/previous() is much faster
than absolute() when the record to be fetched is very near
the last record fetched.  I haven't actually tried it, but
I'd like some insight if others can already answer this
question based on knowledge of the server side and/or the
JDBC driver.

__
David B. Held
Software Engineer/Array Services Group
200 14th Ave. East,  Sartell, MN 56377
320.534.3637 320.253.7800 800.752.8129

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