FetchBufferSize IBM data server driver configuration keyword

Specifies the default query block size to optimize the data flow.

Equivalent CLI keyword

Equivalent IBM® data server provider for .NET connection string keyword

FetchBufferSize

IBM data server driver configuration file (db2dsdriver.cfg) syntax

<parameter name="FetchBufferSize" value="64K | 96K| 128K|
160K| 192K| 224K|
256K |..|10208k"/>

Default setting:

64K

Equivalent connection attribute:

SQL_ATTR_FET_BUF_SIZE

Usage notes:

The CLI driver, IBM data server provider for .NET, and embedded SQL interface allows query block size only in multiples of 32K (that is 64K, 96K, 128K, 160K, 192K, 224K, till 10208K in multiples of 32K). The FetchBufferSize value that is not in multiples of the 32K query block size is rounded up to the next nearest 32K boundary when they are within the range of 64K-10208K. Value that is set outside the valid range (64K to 10208K) is rounded to the next nearest 32K block size that is in the valid range.

CLI applications can obtain the FetchBufferSize value that is set with the SQLGetConnectAttr() function. If the FetchBufferSize keyword is not set to any value, the default query block size is returned.

For embedded SQL applications, the query block size can be specified only with the FetchBufferSize keyword. If the FetchBufferSize value that is outside the allowable range is specified, a warning is logged in the db2diag.log file and the default value is used. In the SQLCA structure, the SQLWARN0 field is set to 'W' and the SQLWARN5 field is set to 'D', indicating that the default value is used instead of the invalid value.