Teradata custom restart
allows a step to be restarted where the load stopped rather than being
started from the beginning of the step. Teradata custom restart is
available when loading from a SAS or other DBMS source that is not
on the same server as the Teradata target. This might include a work
table coming into the step. Custom restart is not available when Upsert
is selected.
When custom restart
is supported, the step determines the last good checkpoint, and the
row number is saved as the restart number. After the error condition
is fixed by an administrator (for example, the database size has been
extended), the next run of that job will start loading the target
table where it stopped.
The load styles that
are available on the Teradata loader for SAS to Teradata loads are:
-
Determine load technique
at runtime
-
-
-
-
Trickle Feed Update
(TPUMP)
-
Upsert (Multiload/Upsert)
When restart is used, and when the
Determine
load technique at runtime option is selected, the same
technique that was used in the first run is used during the restart.
Using the
Use TPT Utilities option with the
Determine
load technique at runtime option provides a more seamless
restart because Fastload without TPT does not support restart through
the access engine, which calls the TPUMP functionality multistatement.
Other TPT and load style combinations result in the following manner:
-
When TPT is set, Multiload will
generate CHECKPOINT=xxx
-
When TPT is not set, Multiload
will generate ML_CHECKPOINT=xxx
-
Regardless of the TPT setting,
CHECKPOINT=xxx will be generated when Fastload is used
The
Use
TPT Utilities check box is located on the
Load Technique tab of the Teradata Table Loader's properties
window. This check box is available if the source table is not in
the same Teradata database as the target table and if one of the load
styles for the Teradata loader except for
Upsert (Multiload/Upsert) is selected. When this check box is selected, SAS Data Integration
Studio uses the Teradata parallel transporter (TPT) API for loading
data. You can select additional TPT options in the
TPT window located on the
Teradata Options tab
in the
Table Options tab in the Teradata
Table Loader properties window.