Donald K. Burleson
Oracle Large Object (LOB) Storage
Actually a special form of tablespace, the large object (LOB)
storage should be on fast disk resources simply due the large
required sizes of most LOB data items. LOB storage should be placed
away from other types of storage and should contain only LOB (LOB,
CLOB, NCLOB, and BLOB) data items. In the 8.0 LOB environment you
could specify separate storage for LOB segments and their associated
LOB indexes, in 8i and greater they are collocated so don't forget
to allow for the LOB and its associated LOB index.
Oracle BFILE Storage
A BFILE is a pointer to an external LOB file. Generally, the same
considerations given to LOB storage will apply to the storage areas
that BFILEs point toward. BFILEs themselves are just internal
pointers to external files and don't require storage areas.
Oracle and Disk Usage
One of the major arguments against relational database systems has
been speed. It has been said that relational systems are slow. It
has been found, however, that with proper tuning of Oracle
applications and operating system, as well as proper file placement,
Oracle performance is excellent. In fact I have seen Oracle8i
deliver subsecond response times even when searching tables
containing billions of rows (yes, I said billions.) Conversely, if
you try to place Oracle on an insufficient number of disks,
performance will suffer.
This is an
excerpt by Mike Ault’s book “Oracle
Administration & Management”. If you want more current Oracle tips
by Mike Ault, check out his new book “Mike
Ault’s Oracle Internals Monitoring & Tuning Scripts” or
Ault’s Oracle Scripts Download.