Which of the following statements about compression for BLU MPP tables is TRUE?
Which of the following statements about compression for BLU MPP tables is TRUE?
Each table has a single compression dictionary that gets replicated across all partitions. This ensures that data consistency is maintained across partitions without requiring decompression when transferring data between partitions.
The answer A is wrong because the columns are automatically compressed with DB2 Blu technology.
The answer D is correct. Indeed, “Actionable compression” is the term IBM uses for the compression that is applied to each column – it uses frequency-based compression (Huffman coding) and other techniques to achieve very high compression ratios. It is “actionable” because predicates can be applied to the column without uncompressing the data. With multi-partition tables, DB2 does not generate unique compression dictionaries for each partition – each table has a single dictionary that is replicated across all database partitions. This ensures that DB2 does not have to uncompress the table’s data when sending data between partitions.