[Lazarus] I thought it was solved -- TQuery.Open very slow.

[Howard Lee Harkness]

I have added some code to only open a query if the corresponding
tabsheet is selected, which I think speeds things up sufficiently.
Still would like to know why a TQuery component would take 2 or 3
seconds to open, even on a slow machine.

Here is the SQL from my address table query:

select * from addresses
where ID = :ID
order by atype,asof

"atype" is a string (home, work, etc.) and "asof" is a date.

The SQL for the other two queries is very similar.

In the synchronization procedure to set the :ID value for each query:

   closeDependentQueries;
   CurrentClientID := qClients.FieldByName('ID').AsInteger;
   qAddresses.Params.ParamByName('ID').Value := CurrentClientID;
   qCases.Params.ParamByName('ID').Value := CurrentClientID;
   qPhones.Params.ParamByName('ID').Value := CurrentClientID;

I have not yet played around with the foreign key stuff, and I'm not
really sure how to enable & use foreign keys in SQLite, anyway.

On Mon, Aug 1, 2011 at 4:21 PM, Howard Lee Harkness
<howard.lee.harkness at gmail.com> wrote:
> I have a dummy database and complete program I can let you look at if
> you would like. Nothing particularly proprietary about the code; it's
> a trivial application. The database is the sensitive part, and I have
> it dummied out.
>
> I posted the schema a few days ago, and I've added a zipcode table to
> that. I had initially thought I had solved the performance problem,
> but when I got to the client, and ran it on his machine (which is
> about 100x slower than mine). I had not noticed the lag on my machine,
> but it was really awful on his.
>
> The whole project is in a 1.6Mb zip, expands to just over 7Mb. Would
> you like me to email it directly to you, or post it?
>
> On Mon, Aug 1, 2011 at 1:56 PM, Michael Van Canneyt
> <michael at freepascal.org> wrote:
>>
>>
>> On Mon, 1 Aug 2011, Howard Lee Harkness wrote:
>>
>>> I thought I had fixed the performance problem, but it is still there.
>>> What I am doing is opening 3 dependent queries after selecting a
>>> record in the main table. It takes 8 or 9 seconds to do the 3 calls to
>>> TQuery.Open. Any clues as to what I might be doing wrong? The sample
>>> queries done from sqlite3.exe return instantaneously, so I am
>>> concluding that I have not set something up correctly in the LCL.
>>
>> Can you provide test data and a sample program ? Without that, it's very
>> hard to give recommendations.
>>
>> The architecture of the sqlite components is not fundamentally different
>> from
>> the other database, and those do work instantaneously.
>>
>> Michael.
>>
>> --
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>>
>
>
>
> --
> Howard Lee Harkness
> (214) 390-4896
>



-- 
Howard Lee Harkness
(214) 390-4896