Options for Hadoop Environments

The following table options are valid only for HADOOP=YES domains.

ACCELWHERE=

The ACCELWHERE= table option enables a user to override the default state of an undeclared WHERE processing optimization (HADOOPACCELWH=) setting. When SPD Server is using a Hadoop environment, and the SPD Server WHERE processing optimization feature state is not defined in the SPD Server parameter file, the default configuration reverts to NO WHERE processing optimization. You can override an undeclared HADOOPACCELWH= setting by issuing a statement that contains the ACCELWHERE= table option set to YES.

If your SPD Server administrator has enabled WHERE processing optimization via the HADOOPACCELWH= setting, you can use the ACCELWHERE= table option to override and suppress the Hadoop WHERE processing optimization. To override and suppress a HADOOPACCELWH=YES setting, issue a statement that contains the ACCELWHERE= table option set to NO.

Syntax

ACCELWHERE=YES | NO

Default

If undeclared, ACCELWHERE= defaults to the value specified in the server HADOOPACLWHERE setting.

Arguments

YES

overrides the default state of an undeclared HADOOPACCELWH= WHERE processing optimization server parameter option. An undeclared HADOOPACCELWH= server parameter option defaults to NO. Submitting the table option ACCELWHERE=YES overrides the default state of the undeclared server parameter option. If the HADOOPACCELWH= parameter option is set to NO (instead of undeclared), ACCELWHERE= table option settings are ignored, and WHERE processing optimization is not performed.

overrides (turns off) WHERE processing optimization if it was previously configured via a HADOOPACCELWH=YES statement in the SPD Server parameter file.

Macro Variable Equivalent

The macro variable equivalent to the ACCELWHERE= table option is the SPDSACWH= macro variable. Setting SPDSACWH=YES is equivalent to setting ACCELWHERE=YES. If a conflict exists from settings specified via the ACCELWHERE= table option and the SPDSACWH= macro variable, the setting specified in the ACCELWHERE= table option takes precedence. For more detailed information about the SPDSACWH= macro variable, see Variables to Enhance Performance.

Example

PROC PRINT data=my_lib.my_table(ACCELWHERE=YES)
  where x=1;

Note: Because SPD Server is able to operate in select Hadoop environments, you might need to determine whether a LIBNAME resides in a Hadoop domain. To determine whether the LIBNAME my_lib is in a Hadoop domain, submit the following LIBNAME LIST statement:LIBNAME my_lib LIST;. If the queried LIBNAME is in a Hadoop domain, SPD Server returns HADOOP=YES to the LIBNAME LIST query.

PARALLELREAD=

Use the PARALLELREAD= table option to enable parallel reads by SPD Server when a WHERE clause is not specified. By default, SPD Server performs multi-threaded reads only when a WHERE clause is specified. The PARALLELREAD= table option configures SPD Server to perform parallel reads when no WHERE clause is specified.

Syntax

PARALLELREAD=YES|NO

Default:UNSPECIFIED (no supplied value)

Arguments

YES

SPD Server performs multi-threaded reads whenever possible, regardless of whether a WHERE clause is invoked.

SPD Server performs multi-threaded reads only when a WHERE clause is invoked.

Description

PARALLELREAD= enables SPD Server users to perform parallel table reads when no WHERE clauses are used.

Corresponding Macro Variable:

SPDSHPRD=YES|NO

If both the PARALLELREAD= table option and the SPDSHPRD= macro variable settings have specified values, the PARALLELREAD= table option setting overrides the SPDSHPRD= macro variable setting.

Note: Because SPD Server is able to operate in select Hadoop environments, you might find a need to determine whether a LIBNAME resides in a Hadoop domain. To determine whether the LIBNAME my_lib is in a Hadoop domain, submit the following LIBNAME LIST statement:LIBNAME my_lib LIST;. If the queried LIBNAME is in a Hadoop domain, SPD Server returns HADOOP=YES to the LIBNAME LIST query.