3 functions and features, Staging tables, Parallel streams – HP Neoview Release 2.4 Software User Manual
Page 21: Parallel query extract
3 Functions and Features
In addition to standard load and extract, Transporter provides support for these additional
features and functions:
•
•
•
“Parallel Query Extract” (page 21)
•
•
“JMS Trickle Feed For Data Loads” (page 22)
•
“Transporter Job Statistics on the Neoview Platform ” (page 22)
•
•
Staging Tables
A staging table is a Neoview SQL table used as an intermediate place for data before it is processed
and moved to the target table on a Neoview platform. Transporter creates the staging table in
the same schema as the target table, names it, uses it during the load operation, and deletes it
when the load operation is complete.
You cannot use staging tables for extract operations.
Use the
option in the control file to control the use of staging tables.
Staging tables increase performance for load operations. However, if the operation fails:
•
You cannot perform recovery if a job failed during transfer from the staging table to the
target table row, you must restart the entire operation.
•
If recovery is not performed, the staging table is not deleted. Check the daily log file in
NVTHOME/log/java
to find the filename and drop the leftover staging table. The staging
table is deleted automatically if recovery is performed. For information about recovery, see
.
Parallel Streams
Transporter supports the use of parallel streams for data movement. Whenever possible,
Transporter uses the parallel stream feature so that data movement is fast and efficient.
You determine the number of parallel streams with the
option in
the control file. For an extract operation, you also supply a filename prefix for the target filenames,
and Transporter creates the necessary target files.
Using parallel streams can increase performance for load and extract jobs. However, because a
larger number of parallel streams increases overhead on the client system, you must determine
the best number of streams to use for maximum performance.
TIP:
Begin by using the default number of parallel streams and then tune your number of
parallel streams based on the performance you observe.
Parallel Query Extract
Transporter enables you to use a single source query to generate multiple parallel data streams
from the Neoview platform. For more information, see the
control
file option.
Staging Tables
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