15.10 - NoSpool Mode - Parallel Transporter

Teradata Parallel Transporter Application Programming Interface

prodname
Parallel Transporter
vrm_release
15.10
category
Programming Reference
featnum
B035-2516-035K

NoSpool Mode

The NoSpool mode exports the contents of a table as fast as possible without reading the table into a spool file or distributing the file to all AMPs before extracting it. Three options for spooling are:

  • (Default) SPOOL the data.
  • Use the NOSPOOLONLY mode, but return an error if NOSPOOL is not supported.
  • Use the NOSPOOL mode when possible; otherwise spool the data in Teradata Database.
  • Limitations and Functionality

  • NOSPOOL mode applies only to simple SELECT statements. The following are not supported:
  • Access to nondata tables, such as SELECT DATE or SELECT USER
  • USING modifier; instead, define restraint parameters by using a FastExport IMPORT command with supporting FIELD and FILLER commands
  • Contains a SORT (ORDER BY), HAVING, or WITH clauses
  • Joins
  • Aggregations (Explain shows SUM step)
  • TABLE functions
  • Ordered-analytic (OLAP) functions
  • Multiple SELECT statements or multistatement requests
  • Statements with zero or more than one, retrieve or sampling step
  • NOSPOOL mode only retrieves data from a single table, but the SELECT statement can be selective about which columns are exported and can constrain the job to a subset of rows.
  • Scalar expressions/functions are allowed.
  • The Sample and partition eliminating constraints are supported.
  • The Activity Count returned for a regular spooled job indicates the number of affected blocks; however, for non-spooled jobs, the number of blocks is unknown, so the response message contains ActivityType (instead of Activity Count) to indicate the NOSPOOL process.
  • Disadvantages of the NOSPOOL Mode

  • Locks are maintained during the entire export process.
  • Data conversion errors previously detected during the spooling phase will not be detected until the block is read, which could occur during any time during the export.
  • Row order (because of the absence of the ORDER BY clause) may or may not be consistent between runs; therefore, NOSPOOL mode offers no guarantee of consistency.
  • For information on Spool/NoSpool mode, see Teradata FastExport Reference.