DTM Buffer

DTM buffer is a temporary storage area for storing temporary data for caching data used by transformation.  Buffer is divided into blocks. The buffer size and block size for a session is tunable.

We can find out number of blocks using formula,

(Number of Blocks)=0.9*((DTM Buffer Size) / (Buffer Block Size))

Slow Reader, Writer or Transformation thread can be an indication requirement for DTM buffer tuning.

                 

    Tuning the DTM buffer:               

§  Buffer block size:

·         At least  100 rows/block is recommended.

·         Block size should be calculated by taking the maximum size for a row.

·         Number of blocks can then be calculated using the formula.

§  Buffer size should be increased by multiple of blocks.

DTM buffer size configuration in an Informatica session:

 

Configure DTM buffer block size:

To utilize the increased DTM buffer, we should also increase the commit interval to some large value to reduce the number of writes to the database.