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Posted by Neil on 11/04/30 11:29
>>> If you don't access slowly populates list items in the background,
>>> and can take a very long time to complete, even if the number of rows is
>>> small, but especially if it is large.
>>
>>I think you forgot a noun or a verb in the above, so I don't really
>>understand what you're saying. Could you rephrase it?
>
> I was missing a comma. To rephrase... If you don't read the whole list by
> selecting the last row in the combo box or by getting its list count,
> Access
> will slowly retrieve the combo box rows in the background, it may take a
> very
> long time, and some locks will be held for duration. Locks can be held
> for a
> long time even by combo boxes with fairly few rows.
Right. (Isn't it fun working with a product like Access whose name can be a
noun or a verb? :-) )
What's strange, though, is that it happened multiple times. You'd think that
after the combo box went to the last record (and a resulting fast go to),
that it would have the list in cache and subsequent go to's would be fast.
But each time it was slow, even one right after the other.
Also, another interesting point is how the limit to list was the pivital
feature. You would think that, whether limit to list was set or not, that
Access would still need to populate the whole list, so the results would be
the same. I guess it has to cross-check the list with limit to list, so
maybe that's the difference.
N
>
>>
>>I'll just note that I didn't consider the combo boxes because the two
>>forms
>>were identical, and I didn't recall changing anything there. So when I
>>compared the two forms, I only compared the code modules and the form
>>properties. I didn't examine the combo box properties.
>>
>>However, in light of the above, I took a closer look at the combo boxes,
>>since, even though your explanation makes sense, it doesn't explain why go
>>to's are always fast on the new version of the form, even with the combo
>>box
>>there. So I took a look at the two combo boxes, and, on the new version of
>>the form, where there's no problem, that combo box is *not* set to limit
>>to
>>list, whereas the original one was. (I must have changed it as I was
>>working
>>with the form.) So, apparently, that's the difference.
>>
>>To confirm this, I went into the new version of the form, set the combo to
>>limit to list, and, voila!, it was slow like the other. Then I changed it
>>back to not limit to list, and it was fast again.
>>
>>So I'm relieved to know that it's not a gremlin that's causing this.
>>
>>Thanks again for your help.
>>
>>Neil
>>
>>
>>>
>>> On Sun, 16 Oct 2005 19:10:46 GMT, "Neil" <nospam@nospam.net> wrote:
>>>
>>>>I have a very puzzling situation with a database. It's an Access 2000
>>>>mdb
>>>>with a SQL 7 back end, with forms bound using ODBC linked tables. At our
>>>>remote location (accessed via a T1 line) the time it took to go to a
>>>>record
>>>>was very slow. The go to mechanism was a box that the user typed the
>>>>index
>>>>value into a combo box, with very simple code attached:
>>>>
>>>>with me.RecordsetClone
>>>> .FindFirst "[Index] = " & me.cboGoTo
>>>> If Not .NoMatch Then
>>>> Me.Bookmark = .Bookmark
>>>> End If
>>>>end with
>>>>
>>>>Now, one would say that going to a record is slow because I'm using
>>>>.FindFirst over a T1 line. And that's what I thought. However, as I was
>>>>working with the form, commenting out various sections not related to
>>>>the
>>>>Go
>>>>To, I found that the Go To functionality changed, though I didn't modify
>>>>the
>>>>code.
>>>>
>>>>Previously, going to a record near the end of the 50,000 record
>>>>recordset
>>>>took about 1-2 seconds, but going to a record near the beginning, took
>>>>about
>>>>20 seconds. After the form changed, going to any record in the recordset
>>>>took about 1-2 seconds.
>>>>
>>>>So the question remains: why did it take so long to go to a record near
>>>>the
>>>>beginning of the recordset, but not near the end (and the ones in the
>>>>middle
>>>>took an amount of time about halfway between the two), and what changed
>>>>so
>>>>that now the form is working fine for all records?
>>>>
>>>>I've compared the changed form with the previous copy, and I don't see
>>>>any
>>>>differences. I've compared all code in the form module, and I've
>>>>compared
>>>>all form properties. The forms are identical as far as I could tell. But
>>>>something happened as I was commenting/uncommenting code in the form
>>>>that
>>>>got rid of the problem with it taking a long time to go to some of the
>>>>records.
>>>>
>>>>My first thought was that something got recompiled, and now the form is
>>>>fast. So I went back to the original version and changed some code and
>>>>recompiled, also did a compact and repair. But it was still slow. I also
>>>>tried doing an explicit decompile and then recompiled it. But it was
>>>>still
>>>>slow.
>>>>
>>>>So this is very frustrating that the form is now working fine, but I
>>>>can't
>>>>see anything that's changed. If I don't see why the form is now fast,
>>>>then
>>>>there's no reason to believe that it might not at some point go back to
>>>>being slow again. And then I'd just have to hope that something changes.
>>>>It
>>>>would be good to figure this out.
>>>>
>>>>Any ideas as to what might have changed here to cause the form's Go To
>>>>to
>>>>be
>>>>fast would be appreciated.
>>>>
>>>>Thanks,
>>>>
>>>>Neil
>>>>
>>>
>>
>
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