Specifies the number of rows of DBMS data to read into the buffer.
| Valid in: | DATA and PROC steps (when accessing DBMS data using SAS/ACCESS software) |
|---|---|
| Category: | Data Set Control |
| Aliases: | BUFF=, BUFFSIZE= [Oracle] |
| ROWSET_SIZE= [Amazon Redshift, DB2 under UNIX and PC Hosts, DB2 under z/OS, Impala, Microsoft SQL Server, Netezza, ODBC, OLE DB, Oracle, PostgreSQL, SAP ASE, SAP HANA, SAP IQ] | |
| ROWSET= [Greenplum, Informix, SAP IQ] | |
| Default: | LIBNAME option value |
| Restrictions: | When READBUFF=1, only one row is retrieved at a time. |
| Buffering data reads can decrease network activities and increase performance. However, because SAS stores the rows in memory, higher values for READBUFF= use more memory. In addition, if too many rows are selected at once, rows that are returned to the SAS application might be out of date. For example, if someone else modifies the rows, you do not see the changes. | |
| Oracle: The default is 250 rows per fetch. Although this value can be up to 2,147,483,647 rows per fetch, this depends on available memory. A practical limit for most applications is less, so the total maximum buffer size must not exceed 2GB. | |
| Interaction: | Hadoop: This option is applied only when READ_METHOD=JDBC. |
| Data source: | Amazon Redshift, Aster, DB2 under UNIX and PC Hosts, DB2 under z/OS, Google BigQuery, Greenplum, Hadoop, HAWQ, Impala, Informix, JDBC, Microsoft SQL Server, Netezza, ODBC, OLE DB, Oracle, PostgreSQL, SAP ASE, SAP HANA, SAP IQ, Snowflake, Spark, Vertica, Yellowbrick |
| Notes: | Support for Yellowbrick was added in SAS 9.4M7. |
| Support for Hadoop, JDBC, and Spark was added in SAS 9.4M8. | |
| Support for Informix was added in SAS 9.4M9. | |
| Tips: | This option improves performance by specifying a number of rows that can be held in memory for input into SAS. |
| The higher the value for READBUFF=, the more rows that the engine retrieves in one fetch operation. | |
| See: | INSERTBUFF= LIBNAME option, INSERTBUFF= data set option, READBUFF= LIBNAME option |
Table of Contents
the positive number of rows to hold in memory. SAS allows the maximum number that the DBMS allows.