Oracle Histograms Simplified: Part 1

Oracle Histogram is very nice feature to help CBO to make right decision while constructing execution plan. But many of DBA’s do not use it, assuming it is complex concept to use. In next few posts, I will try to simplify it, so that we can achieve maximum benefit from […]

Drop empty tablespace fails with ORA-14404 or ORA-144047 partitioned table contains partitions/subpartitions in a different tablespace

Recently I was performing database reorg operation on one of pre-prod environment with traditional way of table/lob movement followed by index rebuild. After moving all segments from current tablespace to new, I was ready to drop original one. SQL> select count(0) from dba_segments where tablespace_name=’MY_TABLESPACE’;   COUNT(0) ———-      […]

ORA-01450: maximum key length (6398) exceeded while creating index

Interesting issue happened today, while creating index in database(running DB on Linux), I got ORA-01450: maximum key length (6398) exceeded. Connected to: Oracle Database 11g Enterprise Edition Release – 64bit Production With the Partitioning, Automatic Storage Management, OLAP, Data Mining and Real Application Testing options SQL> CREATE INDEX […]

OUI-67073:UtilSession failed: Prerequisite check “CheckActiveFilesAndExecutables” failed on Windows server

Few days back, I was applying OPatch on one of the database residing on windows server. I tried it multiple times without any luck as everytime when I tried applying patch, I was getting below error: OUI-67073:UtilSession failed: Prerequisite check “CheckActiveFilesAndExecutables” failed. This was due to some of the DLL […]

ORA-27054: NFS file system where the file is created or resides is not mounted with correct options

From last two days, I have been getting “ORA-27054: NFS file system not mounted with correct options” error while running an RMAN backup to a Sun ZFS Storage Appliance. This error have been observed particularly, while taking controlfile backups. RMAN datafile or archivelog backups without controlfile were running fine. RMAN-08132: WARNING: […]