29th Aug

Flyway database migrator

Monday, August 29, 2016 - 19:06
Author: Juhász László
Usually our applications are not used in only one environment. Each environment has its own database. These databases can be different. When we upgrade our application we have to know which database changes had been made on this given environment and which is not. This can be a huge task and can cause errors when we had more clients with more environments.Flyway can help manage this problem. The way as Flyway helps us is the following. Every database is aware of its own sate. When we make changes on the database with the help of Flyway, it checks the actual database’s version number which is
11th Jan

Oracle vs Microsoft SQL Server

Monday, January 11, 2016 - 13:06
Author: Borovszky Tamás
Performance comparison in a real business application  Why?​Last year we had a project in which we had to upgrade one of our client’s Clavis Security BackOffice system. One of the most important requirements was to reach a better performance in the next 5 years. The previous system used MSSQL and the new uses Oracle. We wanted to know how only the database engine influences the performance. There are plenty of performance tests on the internet between MSSQL and Oracle but unfortunately these are basically synthetic tests so we cannot get appropriate conclusions how our system works
12th Nov

SMS küldés szolgáltatás fejlesztése

Thursday, November 12, 2015 - 11:08
Author: Rimay Csanád
Ez a bejegyzés projekt oldalról szeretné bemutatni az SMS küldés fejlesztésének folyamatát. 2012-ben egy nagybanki partnerünk megrendelésére írtunk egy adatbázis alapú SMS küldő szolgáltatást. Szerették volna SMS üzenetben értesíteni ügyfeleiket, amikor valami pénzmozgás történik a számlájukon.Az ügyfél felőli feladat az volt, hogy a CLAVIS -ban felvett bizonyos tranzakciókról az ügyfelek kapjanak SMS értesítést. A DORSUM -ban ez a feladat inkább úgy nézett ki, hogy írjunk egy olyan SMS küldő szolgáltatást, ami könnyen paraméterezhető, újrafelhasználható és nem tartalmaz céges
23rd Jul

ORACLE database errors 2.

Thursday, July 23, 2015 - 09:23
Author: Fegyver Gyula
ORA-00060: deadlock detected while waiting for resource Whenever you have competing DML running against the same data, you run the risk of a deadlock. If your ORA-00060 is caused by competing resources, (Task B) attempts to lock a row which is being held by another task (Task A), which, in-turn, is waiting for task B to release a lock.  To prevent a perpetual wait, Oracle aborts the transaction that caused the deadlock.What in situations are happening deadlocks in ORACLE database?CASE ONE The most trivial, when we use concurrent DML statements, for example: Error: In
22nd Jul

ORACLE database errors 1.

Wednesday, July 22, 2015 - 11:56
Author: Fegyver Gyula
ORA-04091 mutating trigger/function may not see it I think this is not a rare error in development. Basicly this error can occur when using triggers, or stored functions.Let's see an example by TRIGGER: create or replace trigger TRI_UGYFEL_exmp after insert on UGYFEL for each row declare vv varchar2(128); begin select description into vv from ugyfel where id = :new.id; end; / and the next command: insert into ugyfel (id, description, modify_dt, modify_uid, illetoseg, mobil_lock_state,web_lock_state,web_sms_service,cc_lock_state,