The LIBNAME Statement for Relational Databases PREFETCH= LIBNAME Option 111
Syntax Description
numeric-value
is any multiple of 512, up to the limit of the maximum network packet size setting on
your server.
Details
If you omit PACKETSIZE=, the default for is the current server setting. You can query
the default network packet value in ISQL by using the SYBASE
sp_configure
command.
PREFETCH= LIBNAME Option
Enables the PreFetch facility on tables that are accessed by the libref defined with the LIBNAME
statement
Valid in:
the SAS/ACCESS LIBNAME statement
DBMS support: Teradata
Default value:
not enabled
Syntax
PREFETCH=‘unique_storename,[#sessions,algorithm]’
Syntax Description
unique_storename
is a unique name that you specify. This value names the Teradata macro that
PreFetch creates to store selected SQL statements in the first run of a job. During
subsequent runs of the job, SAS/ACCESS presubmits the stored SQL statements in
parallel to the Teradata DBMS.
#sessions
controls the number of statements that PreFetch submits in parallel to Teradata. A
valid value is 1 through 9. If you do not specify a #sessions value, the default is 3.
algorithm
specifies the algorithm that PreFetch uses to order the selected SQL statements.
Currently, the only valid value is SEQUENTIAL.
Details
Before using PreFetch, see the PreFetch description in the SAS/ACCESS
documentation for Teradata for a complete discussion, including when and how the
option enhances read performance of a job that is run more than once.
