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

Data Set Options for Relational Databases 4 MULTILOAD= Data Set Option 343transferred from SAS to Teradata using shared memory. The default shared memorybuffer size is 64K. The default number of shared memory buffers used for the transferis 2. You can use BUFFERS= to vary the number of buffers for data transfer from 1 to8. You can use MBUFSIZE= to vary the size of the shared memory buffers from the sizeof each data row up to 1MB.Temporary Tables The Teradata MultiLoad utility uses four different temporarytables when it performs the bulk-load operation. It uses a log table to track restartinformation, two error tables to track errors, and a work table to hold data before theinsert operation is made.By default, the SAS/ACCESS MultiLoad facility generates names for thesetemporary tables, where randnum represents a random number. To specify a differentname for these tables, use ML_RESTART=, ML_ERROR1=, ML_ERROR2=, andML_WORK=, respectively.Temporary TableRestart tableAcquisition error tableApplication error tableWork tableTable NameSAS_ML_RS_randnumSAS_ML_ET_randnumSAS_ML_UT_randnumSAS_ML_WT_randnumYou can use ML_LOG= to specify a prefix for the temporary table names thatMultiLoad uses.Here is the order that is used for naming the temporary tables that MultiLoad uses:1 If you set ML_LOG=, the prefix that you specified is used when naming temporarytables for MultiLoad.2 If you do not specify ML_LOG=, the values that you specified for ML_ERROR1,ML_ERROR2, ML_WORK, ML_RESTART are used.3 If you do not specify any table naming options, temporary table names aregenerated by default.Note: You cannot use ML_LOG with any of these options: ML_ERROR1,ML_ERROR2, ML_WORK, and ML_RESTART. 4Restarting MultiLoad The MultiLoad bulk-load operation (or MultiLoad job) works inphases. The first is the acquisition phase, during which data is transferred from SAS toTeradata work tables. The second is the application phase, during which data is appliedto the target table.If the MultiLoad job fails during the acquisition phase, you can restart the job fromthe last successful checkpoint. The exact observation from which the MultiLoad jobmust be restarted displays in the SAS log. If the MultiLoad job fails in the applicationphase—when data is loaded onto the target tables from the work table—restart theMultiLoad job outside of SAS. The MultiLoad restart script displays in the SAS log. Youcan run the generated MultiLoad script outside of SAS to complete the load.You can use ML_CHECKPOINT= to specify the checkpoint rate. Specify a value forML_CHECKPOINT= if you want restart capability. If checkpoint tracking is not usedand the MultiLoad fails in the acquisition phase, the load needs to be restarted fromthe beginning. ML_CHECKPOINT=0 is the default, and no checkpoints are recoded ifyou use the default.