Wrong result returns when Subquery is unnested

A couple of days ago I got a request to take a look at one SQL query, which obviously returns the wrong result. The database version is 12.2 running on Windows on Azure Cloud. Simplified for the demo purpose it looks like this – the query returns 1 and 2, but it should return 1, ...

LMS0: terminating the instance due to error 481

15. December 2016 Uncategorized 1
One production RAC database has been upgraded to 12c and everything went fine for a couple of months, but suddenly after some time, one instance got terminated with the error messages: LMS2 (ospid: 17238): terminating the instance due to error 481 ORA-00481: LMON process terminated with error   The analysis was not so easy. We ...

DataPatch: patch 23177536: The database must be in upgrade mode <- are you serious!?

29. September 2016 Uncategorized 2
Today I applied the latest patchset 12.1.0.2.160719  (July 2016) and afterwards I executed datapatch tool, but got a really stupid error: [oracle/ACME1@acme01 OPatch]$ sqlplus / as sysdba SQL> select  PATCH_ID, PATCH_UID, VERSION, STATUS, DESCRIPTION      from DBA_REGISTRY_SQLPATCH      order by BUNDLE_SERIES;       no rows selected [oracle/ACME1@acme01 OPatch]$ ./datapatch -verbose SQL Patching tool version 12.1.0.2.0 ...

Unified Auditing: some gotchas to be aware of!

Database should be offline when you are enabling pure Unified Auditing or you will get this error: ORA-00600: internal error code, arguments: [krsh_fsga_sgaq.ds_not_found], [], [], [], [], [], [], [], [], [], [], [] By default, in 12c version the auditing runs in mixed-mode, which means you can combine traditional auditing with unified auditing. There ...

“Slow” system & ORA-00445: background process “DIAG” did not start after 120 seconds ?

Since I am currently checking all Oracle systems at the customers site, I thought at first sight, that almost all of them are overutilized or wrong configured, because everything seemed so sloooooow… Especially the new logins and creating of the new processes were a way too slow – more than 5 seconds! Sometimes I waited ...

ORA-07445 [mdcgcvxhl()+4677] using Spatial SDO_GEOM.sdo_convexhull = Bug 22886582

After upgrade of one database to 12c, the customer complained, that one application (which uses Spatial & Graph) isn’t working  properly. After analysing & tracing it, I found the root cause of it – SDO_GEOM.sdo_convexhull. In some cases, this function crashes the whole application raising ORA-03113: ORA-03113: end-of-file on communication channel Process ID: 22675 Session ...

Short list of some bugs to be aware of before upgrading to 12c

03. December 2015 Uncategorized 1
In the last couple of months I was doing a lot of upgrades to the version 12c. I followed the guidelines and the documentation I found on the Oracle homepage, MOS & many blogs, but unfortunately, not every upgrade went smoothly. As always, every new database version brings a couple of new bugs and it ...