Re: Subfile question

Yeah - that's possible, but OFFSET often results in reading all previous rows of the data set - so "performance-wise" its often not the best solution.

Two better solutions:

1. Make the subfile "expanding" and leave the SQL cursor open - but you wont get updated data when reading backwards.

2. Use a scrollable sensitive cursor and scroll forward and backward through the data set - leave the cursor open all the time, so the heaving lifting is only done once.

Done both - both have their pros and cons.

HTH
Daniel

Am 17.07.2024 um 16:28 schrieb Justin Taylor <jtaylor.0ab@xxxxxxxxx>:

I've never tried this, but would this help with SQL and single-page SFL?
OFFSET y ROWS FETCH FIRST x ROWS ONLY

y=start row
x=SFL length



date: Tue, 16 Jul 2024 18:30:44 -0700

from: Reeve <rfritchman@xxxxxxxxx>
subject: Re: Subfile question

I assume the page up/down capability is handled by the workstation
controller. The single-page subfile must be a special case: if I load 200
rows into my 20-line-page-page subfile, I get a workstation controller
error if I try to page past the end. But in a single-page subfile, the
page down key returns control to the application program.

Single-page subfiles were good back in the days of dreadfully-slow
machines. With today's faster machines, taking an extra second to load a
big subfile which the user can page through quickly appears to be a good
design/resource tradeoff. One issue I have with single-page subfiles is
SQL's (or my) inability to read backward, past the starting point, in a
file with multiple keys. There's little I miss about record-level access
except for READE, READP, and READPE...I guess I have to experiment a bit
more!

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