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Hello,

is there something known about memory leaks in your new release of dbxmda driver?

I 've writing a simple tool that makes one connection to a mysql 4.1 backend and sending 1000 (or more) selects (select * from table). Memory is increasing, and not given free. Tested under Kylix3 and Delphi 7.

Thanks in advance

We cannot reproduce your problem with Delphi 7, DbxMda 2.50.6, MySQL 4.1. Send us please small demo project to demonstrate the problem and include script to create server objects to DbxMda support address.

Good news. Windows making TestTool (Delphi 7) has no memory leak. But if I test the same thing under Linux Redhat 7.2 the memory still increase.

A strange thing is when using backend mysql 4.0 every select is very slow but memory increase and decrease, so it seems to be stable. when using mysql 4.1 memory only increases.

Regards Sebastian

My Testapp will follow.

It contains source for Kylix 3 with visualclx patch 3.9 and script for mysql server.

Hello,

any news about reproducing the problem.

Regards Sebastian

We could reproduce the problem but haven't managed to localize it yet.
Try to make these experiments:
- shorten number of columns in Leak and Stable up to minimum
- try to use DbxMda in client mode (by setting DriverFunc)

Hello,

I found out the following thing:

When using TSQLCLientDataSet the memory is increasing in both tables "leak" and "stable".
First time "stable" seems to be stable but it isn't, the memory increase and decrease cause of table size. In table "stable" there are 5600 Records, so after getting the resultset memory increase and when freeing it decrease but it wont give all the allocated memory free. So theres a leak at all, no dependence of table.
And here the strange thing: When using no client dataset f.e. TDataSet there's NO memory leak. But you cant change the data and post it back cause of no clientside. TDataSet is no alternative.
I checked both datasets for leaks with "AQTime for Linux" and found nothing in Kylix Code, so the bug have to be in external library *.so's!

Then i try to find out what the difference between both types of dataset.
When using TSQLClientDataSet there's a library loading called libmidas.so.
This library won't be loaded when using normal DataSet. So i think the bug seems to be in your dbxmda driver when calling methods in libmidas.so or in libmidas.so itself.

Whats your opinion about the above mentioned thing? I hope you could find the bug.

Thanks in advance

Sebastian

DbxMda does not use libmidas.so.
DbxMda uses exactly the same memory allocation/deallocation algorithm for Linux and Windows versions. Other users (mainly Windows) have not informed us about similar problems. So, I think, this is a Kylix bug. Try to make experiments with other dbExpress drivers.

Hello Ikar,

i've wrote an email to dbxmda*crlab*com, but no answer yet. Have you recieved it?

Regards

Sebastian

We got your request and now examines the problem.
Unfortunately now we couldn't give you any information.
As soon as we solve the problem, we'll let you know.

Hello,

i think ther's a mistanderstanding.
In my last mail I asked for a 30 day working linux trial version of MyDac components with no restriction in openning a connection....

Thanks in advance

Answered by email