Find files for a date and time and then copy to a directory

-rw-r--r-- 1 mys1idb oragrid 0 Sep 19 21:23 mys1id5_ora_19242.trc
-rw-r--r-- 1 mys1idb oragrid 0 Sep 19 21:23 mys1id5_ora_19281.trc
-rw-r--r-- 1 mys1idb oragrid 0 Sep 19 21:23 mys1id5_ora_19317.trc
-rw-r--r-- 1 mys1idb oragrid 0 Sep 19 21:23 mys1id5_ora_19325.trc
-rw-r--r-- 1 mys1idb oragrid 0 Sep 19 21:23 mys1id5_ora_19333.trc
-rw-r--r-- 1 mys1idb oragrid 0 Sep 19 21:24 mys1id5_ora_19386.trc

for i in `ls -latR | grep "Sep 19 21" | awk '{print $9}'`; do cp -pr $i /tmp/trace; done

Trick to generate SQL from an Excel File

="INSERT INTO Table (ID, Name) VALUES (" & C2 & ", '" & D2 & "')"

How to resize redo logs for RAC with ASM

Find out the current redo log size

select b.group#,b.thread#,a.member, b.bytes/1024/1024 from v$logfile a, v$log b where a.GROUP#=b.GROUP# order by 1 ;
    GROUP#    THREAD# MEMBER                                                       B.BYTES/1024/1024
---------- ---------- ------------------------------------------------------------ -----------------
         1          1 +RECOVERY/myracdb/onlinelog/group_1.9390.825874743                       1024
         1          1 +RECOVERY/myracdb/onlinelog/group_1.11031.825874749                      1024
         2          1 +RECOVERY/myracdb/onlinelog/group_2.323.825874755                        1024
         2          1 +RECOVERY/myracdb/onlinelog/group_2.11085.825874761                      1024
         3          2 +RECOVERY/myracdb/onlinelog/group_3.324.825874767                        1024
         3          2 +RECOVERY/myracdb/onlinelog/group_3.10010.825874773                      1024
         4          2 +RECOVERY/myracdb/onlinelog/group_4.8913.825874779                       1024
         4          2 +RECOVERY/myracdb/onlinelog/group_4.5641.825874785                       1024

Now create some temporary groups

ALTER DATABASE ADD LOGFILE THREAD 1 GROUP 11 ( '+RECOVERY', '+RECOVERY') SIZE 1024M;
ALTER DATABASE ADD LOGFILE THREAD 1 GROUP 12 ( '+RECOVERY', '+RECOVERY') SIZE 1024M;
ALTER DATABASE ADD LOGFILE THREAD 2 GROUP 13 ( '+RECOVERY', '+RECOVERY') SIZE 1024M;
ALTER DATABASE ADD LOGFILE THREAD 2 GROUP 14 ( '+RECOVERY', '+RECOVERY') SIZE 1024M;

Now you have to keep switch them until you can drop the group 1 thru 4, you can put that in a script and
keep running until you have dropped group 1 thru 4

alter system switch logfile ;
alter system switch logfile ;
alter database drop logfile group 1 ;
alter database drop logfile group 2 ;
alter database drop logfile group 3 ;
alter database drop logfile group 4 ;

Now repeat the process by creating the Group 1 thur 4 with desired size (say 2G each)

ALTER DATABASE ADD LOGFILE THREAD 1 GROUP 1 ( '+RECOVERY', '+RECOVERY') SIZE 2048M;
ALTER DATABASE ADD LOGFILE THREAD 1 GROUP 2 ( '+RECOVERY', '+RECOVERY') SIZE 2048M;
ALTER DATABASE ADD LOGFILE THREAD 2 GROUP 3 ( '+RECOVERY', '+RECOVERY') SIZE 2048M;
ALTER DATABASE ADD LOGFILE THREAD 2 GROUP 4 ( '+RECOVERY', '+RECOVERY') SIZE 2048M;

Now you can drop the temporary groups 11 thru 14

alter system switch logfile ;
alter system switch logfile ;
alter database drop logfile group 11 ;
alter database drop logfile group 12 ;
alter database drop logfile group 13 ;
alter database drop logfile group 14 ;

Redo Threads
Each online redo log has a thread number and a sequence number. The thread number is mainly relevant in RAC databases where
there can be multiple threads; one for each instance. The thread number is not necessarily the same as the instance number.
For single instance databases there is only one redo log thread at any time.

Redo Log Groups
A redo thread consists of two or more redo log groups.

Each redo log group contains one or more physical redo log files known as members. Multiple members are configured to provide
protection against media failure (mirroring). All members within a redo log group should be identical at any time.

Each redo log group has a status. Possible status values include UNUSED, CURRENT, ACTIVE and INACTIVE. Initially redo log
groups are UNUSED. Only one redo log group can be CURRENT at any time. Following a log switch, redo log group continues to be
ACTIVE until a checkpoint has completed. Thereafter the redo log group becomes INACTIVE until it is reused by the LGWR background process.

Log Switches
Log switches occur when the online redo log becomes full. Alternatively log switches can be triggered externally by commands such as:

ALTER SYSTEM SWITCH LOGFILE;

When a log switch occurs, the sequence number is incremented and redo continues to be written to the next
file in the sequence. If archive logging is enabled, then following a low switch the completed online redo log will be copied to the archive
log destination(s) either by the ARCH background process or the LNSn background process depending on the configuration.

ETL Vs ELT - Explanation

Very Nice explanation of the terms ETL and ELT...

http://blog.performancearchitects.com/wp/2013/06/13/etl-vs-elt-whats-the-difference/

- credit goes to the original creator of the content.