How to Demonize Apex V Function! mustafakalayci, 2021-10-31 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… Continue Reading
Hierarchical Blocking Session List mustafakalayci, 2021-10-19 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… Continue Reading
Subquery Caching mustafakalayci, 2021-10-17 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… Continue Reading
Why should you use PLSQL_OPTIMIZE_LEVEL as 3 mustafakalayci, 2021-10-08 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://10.157.89.12/2020/06/26/performance-gain-of-nocopy-parameters/ Very… Continue Reading
ORA-04036: PGA memory used by the instance exceeds PGA_AGGREGATE_LIMIT While Compiling a Huge PLSQL package mustafakalayci, 2021-09-28 Hello everyone, Lately, I faced with an interesting ORA-04036 errors at one of my clients’ development database. My notification modules alerted me about ORA-04036 error and I was just started to investigate trace files (and saw a package name frequently) and one of the developer sent me an email about… Continue Reading
Enable Unified Audit on Linux and Windows mustafakalayci, 2021-09-08 Hi, As you know, since 12c Oracle introduce Unified Auditing which has much more capabilities than standard auditing. Creating policies, audit conditions, top level auditing etc. By default Oracle uses “mixed” mode which allows you to run unified auditing commands and standard auditing. you can check if you are using… Continue Reading
Blockchain vs Immutable tables mustafakalayci, 2021-08-20 Hi, as you know 21c is here for linux and some new features are (as always) pretty exciting. two of them are Blockchain and Immutable tables. Let’s explain and test. first of all, those are new features for 21c but they are backported to 19c. at 19.10 you are able… Continue Reading
Create a Clone DB from Backup on the Same Server (or remote) mustafakalayci, 2021-04-26 Hi, I wanted to create a post series about cloning/duplicating database on the same or remote servers. There are so many options and combinations about this like rman duplicate database with/without target/source db connection, rman restore using backups, ASM to OS or OS to ASM, same server or remote server,… Continue Reading
Pragma UDF & Deterministic mustafakalayci, 2021-04-09 Hello everyone, I wanted to write about something simple and can improve the performance of your sql statements. Unfortunately, many database developers use too much plsql function in their SQL statements. I say too much because if you learn more about the SQL, you will use less plsql. SQL is… Continue Reading
ORA-24244: invalid host or port for access control list (ACL) assignment mustafakalayci, 2020-12-24 Hello everyone, So you wanted to migrate your ACLs to another database or you are trying to add a new acl entity but you got ORA-24244. There are many reasons for that error unfortunately. I wish Oracle provides us more detail about what is the error but I wanted to… Continue Reading