This configuration variable determines the size of the buffer to use when accessing a sequential file whose definition has no BLOCK CONTAINS clause. When set, A_SEQ_DEFAULT_BLOCK_SIZE specifies the size of the buffer in characters, rounded up to the nearest power of 2 that is greater than or equal to that value. The default value is 0, which sets the block size to one record. Note that this variable does not apply to print files or to files with names that start with a hyphen followed by D or P.
You can set A_SEQ_DEFAULT_BLOCK_SIZE in the environment to allow the vutil -load command to buffer the input file according to the variable's value. The maximum buffer size is 1 GB. If this variable is not set, the default buffer block size is 4096 bytes. If it is set to 0, vutil -load performs record-based I/O on a sequential file.