Hp Neoview Release 2.4 Software Manual de usuario descargar pdf (Pagina 21)

3 Functions and Features

In addition to standard load and extract, Transporter provides support for these additional

features and functions:

• “Staging Tables” (page 21)

• “Parallel Streams” (page 21)

• “Parallel Query Extract” (page 21)

• “Prehashing” (page 22)

• “JMS Trickle Feed For Data Loads” (page 22)

• “Transporter Job Statistics on the Neoview Platform ” (page 22)

• “Reflexive Update” (page 22)

• “Identity Columns” (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 “forcestaging” (page 54) 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

“Job Recovery” (page 74).

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 “parallelstreams” (page 57) 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 “parallelstreams” (page 57) control

file option.

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Hp Neoview Release 2.4 Software Manual de usuario Pagina 21