Data Compression

• Hardware & Software Components
  – Hardware (Microcode) provides 4-5 Times Performance
•  Compression at Tablespace or Partition Level
•  Ziv-Lempel Compression Technique
  – Favors De-Compression (Read)
  – Dictionary within TS or Partition
•  Compressed Objects up to 255 Rows/Page
•  Saves DASD, Reduces I/O for Large Scans
•  May save CPU, May cost CPU

Data compression will almost always save large amounts of DASD storage. There may be other benefits, or performance penalties of data compression. This all depends on how the data is accessed, how much of the data you use, and what you do to the data.