Re: Re[2]: Question using jdbc/jt400

On 8/30/07, Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx> wrote:

From: Carl

Then I would wonder if that ResultSet is the set of results you actually
needed?

It is if the user is doing the most fundamental of funcitons: paging through
a list of records by key and positioning the list.

This does not directly address my earlier response which you quoted,
and I maintain that if you find yourself seeking outside the bounds of
your ResultSet, you have either selected the wrong resultSet or your
bounds checking needs work.

Perhaps I was really wondering whether the RPG idiom of SETGT/READP is
even
necessary when using sql, since you can determine the sort order and
collect a result set with the records you actually want in one request,
not two. For example, given a table with a key of a single integer, with
records
1-5, where you wish to read record 4 through 1, in RPG you might write:

Unfortunately, SQL still has no capability to position by key within a
result set. Instead, you must recreate the result set every time. This
fundamental issue has been discussed on this list and on the RPG list (where
it really belongs) many times.

This statement clearly demonstrates to me that you did not understand
the point I was attempting to make, which is that record level random
access may not be needed. I'd be interested in a high level
description of a situation where it is. My question is why you would
need to "postion by key" rather than fetch the records you want and
get to work on them?

Cheers,
Carl.

There is no need to even move backwards in the result set.

The issue is when the user positions themselves in the file and then page
backwards. There simply is no way to do this in SQL without rebuilding the
result set.

It's the fastest way to get the last record in a set without having to

have

indexes in both directions.

Surely if written in RPG, but when writing code in java and using JTOpen
record level access, is the process of requesting a record then
reading the previous (emulating SETGT/READP) faster than issuing a
single sql statement?

Yes.

Joe


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