Source : http://lefterhs.blogspot.co.id/2012/07/archived-log-generation-volume-and.html
V$ARCHIVED_LOG displays information about the archived logs generated by your database and haven’t yet aged out from your control file.
We are going to use this view to generate a report, displaying some useful information about it.
BLOCKS column stores archived log’s size in blocks, BLOCK_SIZE stores block size in bytes, so if we multiply them (BLOCKS*BLOCK_SIZE) we get its size in bytes.
ARCHIVED indicates whether the log is archived and DELETED whether RMAN has deleted it.
The following query displays per day the volume in MBytes of archived logs generated, deleted and of those that haven’t yet been deleted by RMAN.
Bigfile tablespaces are tablespaces with a single large datafile (up to 4G blocks). In contrast normal or smallfile tablespaces can have several datafiles, but each is limited in size. The system default is to create a smallfile tablespace. The SYSTEM and SYSAUX tablespace types are always created using the system default type.
Bigfile tablespaces are supported only for locally managed tablespaces with automatic segment space management, with three exceptions: locally managed undo tablespaces, temporary tablespaces, and the SYSTEM tablespace
Advantages of using Bigfile Tablespaces:
By allowing tablespaces to have a single large datafile the total capacity of the database is increased. An Oracle database can have a maximum of 64,000 datafiles which limits its total capacity.It allows you to create a bigfile tablespace of up to eight exabytes (eight million terabytes) in size, and significantly increase the storage capacity of an Oracle database. Continue reading
You can easily change timezone in CentOS Linux using the following methods.
CentOS timezone config files and directories
/usr/share/zoneinfo/ – The system timezone directory contains the files as per timezone name. For example, the file /usr/share/zoneinfo/America/New_York represents time zone for New York.
/etc/localtime – It is a symlink to the file localtime or to the correct timezone file in the system located in /usr/share/zoneinfo/ directory.
How do I see the current time zone?
Type the date command or the ls command:
$ ls -l /etc/localtime
To find list of all available time zones, run:
# timedatectl list-timezones
##*** Grep possible Asian timezones ***##
# timedatectl list-timezones | grep Asia
…. Continue reading