Memory leak in MySQL 8 with indexed generated virtual columns
Some time ago we have observed that memory for some MySQL instances has been constantly eaten away. Investigation pointed us to memory/innodb/memory area and databases with tables having generated virtual columns, which in addition were used in indexes. It was affecting both 8.0.25 and 8.0.28…
PDB_OS_CREDENTIAL and external jobs
After introduction of Multitenant option, Oracle provided additional ways to ensure proper isolation between pluggable databases. PDB_OS_CREDENTIAL initialization parameter is part of them. It allows to use specified operating system user while interacting with operating system from a PDB. According to documentation, it is taken…
Kerberos Troubleshooting – A few approaches
It is way too long ago since my last blog post. These were or are busy weeks for me. Any way, I finally found some time to start writing a blog post about a special setup for kerberos authentication of Oracle databases. It is about…
Kerberos Troubleshooting – A few approaches
It is way too long ago since my last blog post. These were or are busy weeks for me. Any way, I finally found some time to start writing a blog post about a special setup for kerberos authentication of Oracle databases. It is about…
Kerberos Troubleshooting – A few approaches
It is way too long ago since my last blog post. These were or are busy weeks for me. Any way, I finally found some time to start writing a blog post about a special setup for kerberos authentication of Oracle databases. It is about…
Useful Oracle tools – DBCOMP
Getting lost writes (e.g. ORA-00752: recovery detected a lost write of a data block) is one of the worst DBA’s nightmares. There are a lot of very important questions popping up. Apart from the obvious ones on how to solve the problems reported (hopefully without…
Be careful with ‘save state’ in Data Guard configuration
Users are complaining that from time to time they are connecting to standby database which is opened read-only, instead to primary opened also for writing. What can be the root cause? Previous usage of below command: It keeps not only information about the state of…
Side effect of ExaWatcher workaround for LSOF check
While analysing the problem with ExaWatcher not being able to start, I found quite nasty side effect of a workaround implemented in recent versions of this useful tool. In fact, you will hit it only on Exadata X7 where you had previously implemented another workaround…
Small fix for SQLcl Java problem with Oracle 12.1
Let’s say you want to quickly use some cool features of SQLcl inside the script running on the database server, but only Oracle below version 12.2 is available there (which is the first one being shipped with SQLcl). This means that you have to download…
ExaCC: what to do if dbaas_diag_tool.pl fails
When you open Service Request related to problems on your Exadata Cloud at Customer (or other Oracle Cloud environments), very often you’ll be asked to upload diagnostic data, which can be easily gathered by running /var/opt/oracle/misc/dbaas_diag_tool.pl. If it works… In my case it failed, with…