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
Aggregations (Explain shows SUM step)
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
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
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.