[Solved] Filter dataset, memory growing up?
lazarus / 16-Databases

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lainz · 2019-06-20 22:49

I have a dataset (Offers: TBufDataset;) where I have stored all
"discounts & offers".

Offers.Filter := 'type = 0'
Offers.Filtered := True;

We have 9 kind of offers. The dataset is Filtered to look for the kind
of offer, say offer type 0, offer type 1, and so on.

That procedure grows a lot the memory usage of the program every time
is called. If I remove the filter lines, saying there are no offers,
there is no leak.

It can be that filtering can cause memory grow, but no memory leak is
found at the end of the program?

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valdir.marcos · 2019-06-22 16:29

Quote from: Lainz on June 21, 2019, 12:49:47 amI have a dataset
(Offers: TBufDataset;) where I have stored all "discounts & offers".
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
Offers.Filter   := 'type = 0'Offers.Filtered := True;We have 9 kind of
offers. The dataset is Filtered to look for the kind of offer, say
offer type 0, offer type 1, and so on.
That procedure grows a lot the memory usage of the program every time
is called. If I remove the filter lines, saying there are no offers,
there is no leak.
It can be that filtering can cause memory grow, but no memory leak is
found at the end of the program?Could you provide a small sample
project?

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lainz · 2019-06-22 23:52

Sure, here is a test project that shows the memory growing bug.

On my machine is about 100 kb per second the quantity of memory that
grows and then never comes back (looking at the task manager on
Windows 10).

Edit: to see memory growing faster, increase the number of records
generated to 10000. But take into account that maybe you need to kill
the application then.

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lainz · 2019-06-23 15:10

Reported in bugtracker
https://bugs.freepascal.org/view.php?id=35756

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lainz · 2019-06-23 21:15

Well it was solved as 'Memory Fragmentation' or 'blame the DBGrid'.
With no DBGrid it still increases memory, so it must be the first
choice.

I close this since no one will fix it, because "there are no leaks",
but memory increases anyways, so better not use filter like I'm doing
in the example.

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lainz · 2019-06-25 02:09

Reopen.

Thanks to BrunoK for opening a new issue with a fix
https://bugs.freepascal.org/view.php?id=35759