Data Transformation Engine Resource Adapter Reference Guide

Chapter 5 - Database-specific Adapter Information List of Commands
Resource Adapters Reference Guide
66
Row Count (-RC or -ROWCNT)
(For ODBC, Oracle, DB2 for Windows, and DB2 for UNIX adapters only)
Use the Row Count adapter command (
-ROWCNT) to specify the number of rows to
be retrieved in one fetch from the database by the database adapter. This
command can be used for a source or in a
DBLOOKUP, DBQUERY, or GET function.
-ROWCNT
specifies
the number of rows to
be retrieved from the
database.
Note This adapter command specifies the number of rows that the adapter should
retrieve from the database. It should not be confused with the FetchAs >
FetchUnit card setting that specifies the number of rows the adapter will pass to
the Command Server. For more information about the FetchUnit card setting,
refer to the Database Interface Designer Reference Guide.
FetchUnit
specifies
rows to pass
to server
-ROWCNT
specifies
retrieval from
database
The time to fetch is optimized in accordance with the increase in the number of
rows to be retrieved. Therefore, a significant performance improvement may be
gained by retrieving as many rows as possible in a single fetch.
-ROWCNT
row_count
Without using this command, the default number of rows to be retrieved per fetch
is:
♦ for ODBC, one row
♦ for DB2, one row
♦ For Oracle, a 64K buffer is allocated. Then, a calculation is performed to
determine the number of rows that can be held in the buffer.
Note The factor limiting the number of rows to be retrieved is the memory requirement
because the return buffer must be large enough to hold the rows retrieved.