15.10 - Producer Operators - Parallel Transporter

Teradata Parallel Transporter User Guide

prodname
Parallel Transporter
vrm_release
15.10
category
User Guide
featnum
B035-2445-035K

Producer Operators

The Teradata PT producer operators in this section read data from a Teradata Database and write it to the data stream.

The Teradata PT job script invokes a producer operator, which employs the user-specified SQL SELECT statement to access Teradata Database tables. For further information on using APPLY/SELECT to specify a producer operator, see “Coding the APPLY Statement” on page 64 and the section on APPLY in Teradata Parallel Transporter Reference.

The following table briefly describes and compares the function of each Teradata PT operator that can be used as a producer when extracting data from a Teradata Database:

 

Operator

Description

Export Operator

Extracts large volumes of data from a Teradata Database at high speed. Function is similar to the standalone Teradata FastExport utility.

Features:

  • Allows use of multiple parallel instances.
  • For a sorted answer set, redistribution of the rows occurs over the BYNET. This allows for easy recombination of the rows and data blocks when they are sent to the client in sorted order.
  • Limitations:

  • Cannot be used to retrieve data in TEXT mode and write it to target files in the TEXT or VARTEXT (delimited) format. Use SQL Selector for this where possible.
  • A sorted answer set requires that only a single instance of the Export operator can be used. Specifying ORDER BY in the SELECT statement and multiple Export operator instances results in an error.
  • For details, see Teradata Parallel Transporter Reference.

    SQL Selector Operator

    Submits a single SQL SELECT statement to the Teradata Database to retrieve data from a table.

    Features:

  • Use to retrieve data in TEXT mode and write it to target files in the TEXT or VARTEXT (delimited) format.
  • Can retrieve LOB, JSON and XML data from the Teradata Database.
  • Limitations:

  • Much slower than Export operator.
  • Teradata strongly recommends that you specify XMLSERIALIZE on selected XML columns so that the byte-order-mark (BOM) matches the XML encoding when using the client UTF-16 character set.

    For details, see Teradata Parallel Transporter Reference.