Hi, Answer of the question in the subject is “Using too much V in SQL statements”. Let’s see why and what should you do. First things first, I am NOT a APEX developer. I am a DBA and Database Developer but some of my clients are using APEX and I am dealing with many sql […]
Month: October 2021
Hierarchical Blocking Session List
Hi, Today, I needed to list all blocking sessions hierarchically. As you know, all information about sessions (and blocking sessions) are in gv$session (or just v$session if you are using single instance) view. I wanted to see who is blocking who and blocker at the top. you can write simple connect by (or with clause) […]
Subquery Caching
Hi, I want to talk about very sweet performance “trick”. I love when I do something small and gain a lot 🙂 Today, I will demonstrate subquery caching in Oracle and try to explain how it works and it’s limitations. Probably, you are using some plsql functions in your select (or dml) statements. There is […]
Why should you use PLSQL_OPTIMIZE_LEVEL as 3
Hi, As you know PLSQL_OPTIMIZE_LEVEL parameter is used to optimize the codes while compiling them and it is really important. By default it’s value is 2 but you can increase it to 3 and you should, here is why. before begin, this is an extension for this post: http://mustafakalayci.me/2020/06/26/performance-gain-of-nocopy-parameters/ Very much thanks to Stephan Borsodi who […]