Configure the format properties for flat file sources to enable the Data Integration Service to read source data efficiently.
Consider the following solutions for flat file source bottlenecks:
Do not use quotes or escape characters in the format properties for a delimited flat file.
If you specify an escape character, the Data Integration Service reads the delimiter character as a regular character embedded in the string. You can improve mapping performance slightly if the source file does not contain quotes or escape characters.
Set the number of bytes the Data Integration Service reads per line.
If the mapping reads from a flat file source, you can improve mapping performance by setting the number of bytes the Data Integration Service reads per line. Configure the Line Sequential Buffer Length property in the run-time properties for flat file sources.
By default, the Data Integration Service reads 1024 bytes per line. If each line in the source file is less than the default setting, you can decrease the line sequential buffer length in the mapping properties.