108 MULTI_DATASRC_OPT= LIBNAME Option Chapter 9
Default value: 25
Syntax
MAX_CONNECTS=numeric-value
Details
If you omit MAX_CONNECTS=, the default for the maximum number of connections is
25. Note that increasing the number of connections has a direct impact on memory.
MULTI_DATASRC_OPT= LIBNAME Option
Used in place of DBKEY to improve performance when processing a join between two data sources
Valid in:
the SAS/ACCESS LIBNAME statement
DBMS support:
DB2 OS/390, DB2 UNIX/PC, Informix, ODBC, OLE DB, Oracle,
Microsoft SQL Server, SYBASE, Teradata
Default value:
NONE
Syntax
MULTI_DATASRC_OPT=NONE |IN_CLAUSE
Syntax Description
NONE
turns off the functionality of the option.
IN_CLAUSE
specifies that an IN clause containing the values read from a smaller table will be
used to retrieve the matching values in a larger table based on a key column
designated in an equi-join.
Details
When processing a join between a SAS dataset and a DBMS table, the SAS dataset
should be smaller than the DBMS table for optimal performance. However, in the event
that the SAS dataset is larger than that DBMS table, the SAS dataset will still be used
in the IN clause.
When SAS is processing a join between two DBMS tables, SELECT COUNT (*) is
issued to determine which table is smaller and if it qualifies for an in clause. You can
use “DBMASTER= Data Set Option” on page 180 to prevent the SELECT COUNT (*)
from being issued.
Currently, the IN clause has a limit of 4,500 unique values.
Note: The Oracle DBMS can handle an IN clause of only 1,000 values. Therefore, it
divides larger IN clauses into multiple, smaller IN clauses. The results are combined
