CHA Alert CHA_DBWR_CKPT_IO_COMPLETE in OEM
A customer was getting the CHA_DBWR_CKPT_IO_COMPLETE alerts from Oracle Enterprise Manager (OEM).
This post investigates the root cause.
Заметки¶
SU bypassed: More than 1 column in connect condition
A recent thread on Oracle-L discussed a CBO regression that was encountered following 19.8->19.9 Release Update application.
Tracing Library Cache Locks Using _kgl_debug
A recent blog post from Nenad Noveljic prompted me to review the library cache tracing facilities available in Oracle database.
Diagnosing Cluster Verification Utility (CVU) Errors
A cluster verification utility (CVU) command failed with the PRVF-5157 and PRVF-5431 errors.
This post demonstrates how the errors were diagnosed and the root cause was identified.
Using SEHA Features in EE
Here is a short demonstration how to make use of the Standard Edition High Availability (SEHA) cold failover feature in Enterprise Edition (EE).
Updating non Key-Preserved Table
There used to be the BYPASS_UJVC hint that allowed to update a non key-preserved table.
It is still there, but it must have stopped working around 11.2.
It turns out that Oracle introduced a fix control that seems to be doing the same in 19.10.
OPATCHAUTO-72043 and JCE
I was applying Grid Infrastructure Jan 2021 Release Update (GI RU) 18.13.0.0.210119 to an 18c cluster the other day.
opatchauto failed with the error OPATCHAUTO-72043.
SYS and Extended Data Types
It is a widely known fact that Oracle supports a maximum size of 32,767 bytes for the VARCHAR2, NVARCHAR2, and RAW data types (Extended Data Types) provided that MAX_STRING_SIZE = EXTENDED.
What I recently discovered is that SYS can create such columns even when MAX_STRING_SIZE = STANDARD.
Creating a Table for Exchange and Copying Indexes
It is something Oracle added in one of the latest Release Updates of 19c. I believe I discovered it either in 19.7 or 19.8 originally.
Pluggable Database not Opened on all RAC Instances Following Switchover
Following Data Guard switchover, a pluggable database was not opened on all RAC instances. This post demonstrates the issue and the fix.