SAS/ACCESS 9.2 for Relational Databases: Reference, Fourth Edition

54 Generating Trace Information for Threaded Reads 4 Chapter 6steps that only read tables. Or, DBSLICEPARM=NONE turns it off entirely. You canspecify it as a data set option, a LIBNAME option, or a global SAS option.The first argument to DBSLICEPARM= is required and extends or restricts threadedreads. The second optional argument is not commonly used and limits the number ofDBMS connections. These examples demonstrate the different uses ofDBSLICEPARM=.3 UNIX or Windows SAS invocation option that turns on threaded reads for allread-only libref.--dbsliceparm ALL3 Global SAS option that turns off threaded reads.option dbsliceparm=NONE;3 LIBNAME option that restricts threaded reads to just SAS threaded applications.libname lib oracle user=scott password=tiger dbsliceparm=THREADED_APPS;3 Table option that turns on threaded reads, with a maximum of three connectionsin this example.proc print data=lib.dbtable(dbsliceparm=(ALL,3));where dbcol>1000;run;DBSLICE= and DBSLICEPARM= apply only to DBMS table reads. THREADS= andCPUCOUNT= are additional SAS options that apply to threaded applications. For moreinformation about these options, see the SAS Language Reference: Dictionary.Generating Trace Information for Threaded ReadsA threaded read is a complex feature. A SAS step can be eligible for a threaded read,but not have it applied. Performance effect is not always easy to predict. Use theSASTRACE option to see whether threaded reads occurred and to help assessperformance. These examples demonstrate usage scenarios with SAS/ACCESS toOracle. Keep in mind that trace output is in English only and changes from release torelease./*Turn on SAS tracing */options sastrace=’’,,t,’’ sastraceloc=saslog nostsuffix;/* Run a SAS job */data work.locemp;set trlib.MYEMPS(DBBSLICEPARM=(ALL,3));where STATE in (’GA’, ’SC’, ’NC’) and ISTENURE=0;run;The above job produces these trace messages:406 data work.locemp;407 set trlib.MYEMPS(DBSLICEPARM=(ALL, 3));408 where STATE in (’GA’, ’SC’, ’NC’) and ISTENURE=0;409 run;