I'm sure you all know to use DBMS_STATS to gather statistics for your tables and indexes. The DBMS_STATS.GATHER_TABLE_STATS() method has as its first three parameters OWNNAME, TABNAME, and PARTNAME, specifying the schema owner name, table name, and table partition name, respectively.I had been assuming that specifying a partition name via... [Read More]
CONNECT role, we hardly knew ye.
I knew that in Oracle 10gR2, the CONNECT role had been stripped down to only provide the CREATE SESSION privilege. I did not, however, know that Oracle had officially deprecated the CONNECT role.Count me among the lazy DBAs that Andrew Clarke is referring to. :p
TWO_TASK is actually still used.
You'll have to forgive my obtuseness. I only ever log into my Oracle servers as "oracle" and am able to login locally with$ sqlplus / as sysdbaor$ sqlplus dtsSo today I was a little scared when I couldn't do this from an OS user other than oracle. The $ORACLE_SID variable... [Read More]
The Story of RMAN Duplication and the Pre-Existing Tempfiles
Just a brief note to share with you that if you are performing an RMAN duplication over an existing instance, you'll want to delete your temporary tablespace tempfiles first. Metalink Note 374934.1 can tell you the whys and wherefores. The note also seems to suggest that the problem exists solely... [Read More]
In his paper "Using DBMS_STATS in Access Path Optimization", Wolfgang Breitling writes:Histograms are like drugs -- An overdose [of histograms] can kill [performance].I've gotten a crash course on this recently. More on that in a bit.