Write protection can be applied to tables. This prevents DDL (Data Definition Language) and DML (Data Manipulation Language) changes during maintenance mode. The statement: ALTER TABLE tablename READ ONLY; — nur mehr lesbar ALTER TABLE tablename READ WRITE; — Read and write possible VIEWs can be equipped with a WITH READ ONLY option. This ensures … Read more
In principle, Snippet and Code Template serve the same purpose: Previously created code is inserted at the desired location. The only difference between the two tools is the paste option. Snippets require the Snippets window first. This can be dragged to any location in the SQL Developer. In addition, the snippets are divided into different … Read more
SQL IN list SQL IN Statement (IN lists) can only process and validate 1000 values. Everything about it returns an error. Here’s an example to demonstrate an IN list. Here only employees and workers are shown, which identification number is in the IN list. SELECT * FROM emp WHERE 1=1 AND empNo IN (1, 2, … Read more
This article discusses operational optimization problems and algorithms. Additionally, graphs, paths, and cycles are revisited, and complexity is discussed. The algorithms section delves into heuristics and approximation algorithms, primarily focusing on the Travelling Salesman Problem and the Knapsack Problem. The emphasis here is on generating a valid tour or a valid composition of the problem. … Read more
NVL VS NVL2 The difference between the SQL functions NVL and NVL2 is, that when using the function NVL2 you can set different values for NULL and NOT NULL. NVL only checks and analyzes the first expression. If the expression is NOT NULL, the function outputs the value of the field. If a NULL value … Read more
Sometimes default values are necassary. Normally you can use NVL or NVL2 when you get NULL values as return value. But it is also possible, that no row is returned. In this case, NVL or NVL2 is not working, cause you get no value back – not even NULL. Therefore, there are some options – … Read more
The SQL Developer sets implicit automatic COMMITs. This COMMIT is subconsciously and automatically canceled in the following situations. (1) SQL Developer quits normally, with no COMMIT or ROLLBACK statement. In this case, a COMMIT is sent before the program is terminated. However, this does not happen in the event of a system failure of the … Read more
APEX and Oracle are closely intertwined. For this reason, the APEX also returns Oracle errors. Today I want to tell you how to solve the ORA-20987. Error message Ajax call got server error ORA-20987: APEX – session state protection violation: This error was probably caused because the URL containing a checksum was changed. A link … Read more
What is ITIL 4? ITIL has been a proper name since version 4. However, ITIL used to stand for Information Technology Infrastructure Library. ITIL 4 is largely based on ITIL 3, whereby ITIL 3 is still valid. In February 2019 ITIL 4 appeared, which is a concept for best practice – i.e. a recommendation. However, … Read more
Oracle SQL Developer is slow and you want to tune SQL Developer? Or too slow for you? Then you should tune your Developer Tool. It is really easy and everyone can do it. First you have to find your installation directory. There you have to edit the following file: “sqldeveloper\ide\bin\ide.conf”. You can use Notepad++ for … Read more
