Hello everyone, I have been already write revealing information that control file stores: https://mustafakalayci.me/2020/08/11/control-file-content-and-the-limits/. Data in control file is separated into “SECTIONS” and you can see those sections name (type) via V$CONTROLFILE_RECORD_SECTION view. for example, database separates a section for “BACKUP SET”s. every section has a record size limit . All those information can be […]
Mustafa
Basically, SQL is the third language that I can speak. I work as a consultant and tuning is my favorite area.
Audits are not Purged
Hello, This week I realized that some of my databases’ audit data are not purged and audit tables get bigger. I already have a scheduler job to purge my audit records but somehow job has been completed successfully but audit records are not deleted. This is 19.15 version, NON-CDB databases. I am using unified audit […]
lsnrctl or new db connection is too slow
Hello everyone, I know this is not new but I haven’t seen this problem for a long time and it takes a while to find out it. A team leader (who is an elder brother to me) from the company I started to my first job called me and asked about a problem on their […]
SESSION_CACHED_CURSORS Parameter and How can It Affect the Database
Hello, Let’s talk about the SESSION_CACHED_CURSORS parameter. It might have significant affect on your system so understanding how it works and what it cause is important. This parameter limits the number of cached cursors on the session. As you know there is 2 kind of parse SOFT and HARD. Hard parse is creating the cursor […]
Marked as unrecoverable datafile in V$datafile even if they are not!
Hello, it has been a while since I posted. I lost a close relative to me and it wasn’t easy. So, let’s continue. I run orachk on one my development databases yesterday and result was very informative. Interestingly, I had a “FAILED” check that indicates some of the datafiles are not recoverable! This is a […]
How to Convert LONG to Clob PART 2
Hi, I just want to write a small post today. Some time ago, I shared a way to convert long to clob in a query directly: https://mustafakalayci.me/2020/04/06/how-to-convert-a-long-column-to-clob-in-a-query/ Even if this method works, it works really slow and anything slow annoys me! So, I want to share another method which is much much faster than Sys_dburigen function but […]
Zero Data Loss DISASTER Database for Standard Edition 2
Hi, As you know Data Guard is an Enterprise Edition option and only accepted method to protect your data against a “DISASTER” (DR) is data guard. How about Standard Edition 2(SE2)? Is this possible? Well I did it so, king of yes 🙂 with some risk of course. Warining: I don’t take any responsibility for […]
Indexes with NOSEGMENT a.k.a Virtual Index
Hi, Today, an old trainee has contacted with my on linkedin and we talk about some performance issues about a query. During the conversation I suggest to use “virtual indexes” to simulate the index so I wanted to write about virtual indexes and their benefits in this post. if you don’t work on a large […]
3 Ways to Migrate a Non-CDB Database to a PDB
Hi Everyone, Time is fast and everything is changing constantly. Multi-tenant architecture has come many years ago and starting by 21c, it is the only option! So, old “non-cdb” databases must be migrated/converted to a PDB (Pluggable database). I must admin that I was being lazy for many years and I didn’t work much to […]
STOPPED Job While Migrating Non-CDB to PDB via Autoupgrade
Hi, Lately, I started to learn about autoupgrade which is the new upgrade tool for almost anything. Many thanks to Mike Dietrich for amazing blog posts ( https://mikedietrichde.com ). His blog is a real treasure. I am about to migrate some non-cdbs to pdbs and before doing that I wanted to learn my options about […]