How To Add or Remove Column Statistics (Histograms) For A Column

How To Quickly Add/Remove Column Statistics (Histograms) For A Column [ID 390249.1]

how to delete histograms for a column

How to delete just histograms without regathering column statistics [ID 5579764.8]


what is a qtree

A quota tree, or qtree, is a logical unit used to allocate storage. The system administrator sets the size of a
qtree and the amount of data that can be stored in it, but it can never exceed the size of the volume that
contains it.
The smallest granularity for SnapVault is a qtree; each qtree can contain different application data, have
different users, and meet different scheduling needs. However, the SnapVault Snapshot creations and
schedules of a SnapVault transfer by destination volume. Because the scheduling is on a volume level,
when you create volumes on the secondary storage system, be sure to group like qtrees into the same destination volume


ORA-20110: Unexpected error executing MGMT_SET_JOB_Q_PROC

Grid Control 11g: Post Install Script For PSU Patch 12423703 gives Error: "ORA-20110:Unexpected error executing MGMT_SET_JOB_Q_PROC" (Doc ID 1359157.1)

TNS-12599: TNS:cryptographic checksum mismatch

11gR1 and 11gR2 Target Database or Repository Producing Several TNS-12599 Errors in Alert.log File (Doc ID 1150874.1)


how to store tnsnames in LDAP or ActiveDirectory

A very good tutorial : http://oracle-cookies.blogspot.com/2007/01/get-tnsnamesora-from-openldap.html

Please be aware, that , if you have SUSE or OPENSUSE, it is better to user YAST2 in order to configure openldap , rather than editing directly /etc/openldap/slapd.conf

Also: you can check the following links :

AttributeType inappropriate SUPerior: "c"

The error appears usually, when you try to run an openldap 2.30 version core.schema  or database, with openldap 2.40 binaries .


how to see different optimizer parameters set by the clients

set pages 200 lines 132
col sql_feature for a24
select *
where sid = :sidyour
order by name;

Oracle Server Tech Support “best practices” for statistics

depending on the table size, the sample size is altered per the following schedule to improve speed of execution (these values have been established by Oracle Server Tech Support “best practices”.)
100% for tables < 1M rows
30% for tables up to 10M rows
10% for tables up to 100M rows
3% for tables up to 1B rows
1% for tables > 1B rows

To reduce the risk of this inconsistency impacting the performance of the RDBMS, the gather_schema_stats()procedure forces the gathering of statistics based on the following “best practices” as established by Oracle RDBMS Server Tech GCS:
every 3 weeks for tables < 1M rows
every 4 weeks for tables up to 10M rows
every 5 weeks for tables up to 100M rows
every 6 weeks for tables up to 1B rows
every 7 weeks for tables > 1B rows

SQL Tuning Health-Check Script

See metalink note Doc ID 1366133.1 


ORA-00600: internal error code, arguments: [2116], [900], [], [], [], [], [], [], [], [], [], [] ORA-00600: internal error code, arguments: [2116], [900], [], [], [], [], [], [], [], [], [], []

There is a metalink note ( see below ) about a timeout on opening the controlfile.

The same error can happen if you use DNFS ( direct NFS ) , and somehow... you modify the IP the storage or server.

Until you don't modify oranfstab, you can not mount/open the database, and the same misleading error you have is ORA-00600: internal error code, arguments: [2116], [900], [], [], [], [], [], [], [], [], [], []


Disk file operations I/O

Bug 10361651  File open may hang/spin forever if dNFS is unresponsive

how to run AWR, ADDM and ASH Reports

Run the following scripts from SQLPLUS 



disable automatic space advisor in oracle 11G

    client_name => 'auto space advisor',
    operation   => NULL,
    window_name => NULL);
Also, take a look at : select * from DBA_AUTOTASK_CLIENT
See also metalink note : 11g: Scheduler Maintenance Tasks or Autotasks (Doc ID 756734.1)


how to extract IP from listener.log


an easier way :
   less listener.log | egrep -v 'service_update|ping' | awk -F "HOST=" '{print $2}' |awk -F ")" '{print $1}' | sort |uniq |less



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Ora-07445 Core Dump [Opixrb()+3004]

Ora-07445 Core Dump [Opixrb()+3004] [ID 782454.1]