Databases Reference
In-Depth Information
This data load procedure is not available for Windows as
this platform does not allow the use of the named pipes
required to perform the data load on the fly.
At a Unix prompt, let's create a regular named pipe:
mkfifo abcpipe.dat
Send data to the named pipe and leave the process in the background:
cat abc.dat > abcpipe.dat &
Load data from the named pipe:
sqlldr sqlldrdemo/oracle direct=true control=abc data=abcpipe.dat
It can be seen that SQL*Loader performs the load seamlessly. The data source was
obtained from the named pipe and then read and loaded by SQL*Loader.
You can remove the named pipe, just like any other regular file:
rm abcpipe.dat
The advantage of this approach is that there is no intermediate file created,
saving space and performing a clean one time load from a dynamic data source.
Direct path versus Conventional
path load
If SQL*Loader is properly configured the load can be sped up in a meaningful way
by means of the direct path load. Direct path was a new feature introduced in Oracle
7.3, and it hasn't changed too much since then. Direct path is an Oracle feature that
allows an insertion process to go directly to the database files without using the
database transactional mechanism. It allows the data load process to be performed
in the fastest possible way. It must be noted that there is a price to pay in the
transaction and recoverability models for the increased processing speed.
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