Multi threaded (2 threads) Java program for copy command

Hi Jennie, I am getting below given exception while running in parallel. Exception in thread "main" java.sql.SQLException: COMMIT: transaction is aborted because of concurency conflicts, will ROLLBACK instead at nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.executeQuery(MonetConnection.java:2535) at nl.cwi.monetdb.jdbc.MonetConnection$ResponseList.processQuery(MonetConnection.java:2284) at nl.cwi.monetdb.jdbc.MonetStatement.internalExecute(MonetStatement.java:508) at nl.cwi.monetdb.jdbc.MonetStatement.execute(MonetStatement.java:349) at connect_monetdb.runETL2(connect_monetdb.java:79) at connect_monetdb.main(connect_monetdb.java:14) Thank you, Shivanandan Gupta. On Fri, Mar 13, 2015 at 8:09 PM, Shivanandan Gupta < shivnandangupta@gmail.com> wrote:

Hi Jennie,

Thanks for your reply. please find my replies below:

Jennie Commented: Concurrent insertion into two different tables should work. Do you have anymore information about why the COMMIT has failed? Maybe the problem lies somewhere else than concurrent insertions?

Shiva's Comment: yes when I run two batch file by clicking it with difference of second ( as it takes few seconds to click the second batch file) and it runs perfectly, even I have tried running copy command directly on the monetsql client and on two clients in parallel it works perfectly. Is there some configuration change required on monetdb server?

Jennie Commented: - Have you tried the two COPY INTO separately? To know if the problem is indeed caused by concurrent insertions.

Shiva's Comment: When I am trying with two separate java program running concurrently its throwing same exception.

Jennie Comment: - Does the problem occur one-time, or every time you repeatedly execute your code? Shiva's Comment: Yes the same error message is coming every time I run concurrent java programs with copy command in it ( here copying data to different tables ).

Any help will be really appreciated.

Thank you.

Shivanandan Gupta.

Date: Fri, 13 Mar 2015 15:36:23 +0800 From: Ying Zhang To: Communication channel for MonetDB users Cc: martin@monetdb.org Subject: Re: Multi threaded (2 threads) Java program for copy command Message-ID: <89A66109-B083-45A4-B59E-62B7AF0C9D86@cwi.nl> Content-Type: text/plain; charset=us-ascii

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On Mar 12, 2015, at 19:27, Shivanandan Gupta wrote:

Hi Martin,

Thanks for your prompt reply , I am using two different tables here but still I am getting "Exception in thread "main" java.sql.SQLException: COMMIT: failed" exception.

Hello Shivanandan,

Concurrent insertion into two different tables should work. Do you have anymore information about why the COMMIT has failed? Maybe the problem lies somewhere else than concurrent insertions?

- Have you tried the two COPY INTO separately? To know if the problem is indeed caused by concurrent insertions. - Does the problem occur one-time, or every time you repeatedly execute your code?

Regards,

Jennie

On Thu, Mar 12, 2015 at 4:57 PM, Shivanandan Gupta < shivnandangupta@gmail.com> wrote:

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Hi Martin,

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Thanks for your prompt reply , I am using two different tables here but still I am getting "Exception in thread "main" java.sql.SQLException: COMMIT: failed" exception.

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Message: 2 Date: Thu, 12 Mar 2015 08:32:31 +0100 From: Martin Kersten To: users-list@monetdb.org Subject: Re: Multi threaded (2 threads) Java program for copy command commit fails for one thread Message-ID: <5501410F.1070508@monetdb.org> Content-Type: text/plain; charset=windows-1252; format=flowed

Hi,

Yes. Insertion into the same table would be invalidated due to the transaction semantics. See https://www.monetdb.org/Documentation/Manuals/SQLreference/Transactions