DSN1940I csect-name COMPRESSION REPORT compression-report
Explanation
DSN1COMP completed successfully. This message contains the DSN1COMP compression report. The format of compression-report depends on the type of object specified when the utility was run. For more information and examples, see DSN1COMP output.
- Table space report format
The DSN1COMP utility report for a table space contains estimates for either fixed-length compression, Huffman compression, or both, depending on:- Availability of hardware support for HUFFMAN compression
- The COMPTYPE parameter
- The table space type
availability-status is either available or not available.
For a universal table space, If DSN1COMP was run with
PARM='COMPTYPE(ALL)', or if the COMPTYPE parameter was omitted on IBM z14® or newer hardware, the DN1COMP utility report for a table space has the following format.DSN1940I DSN1COMP COMPRESSION REPORT Hardware support for Huffman compression is availablility-status +-----------------------------------+------------------+------------------+------------------+ | | Uncompressed | Compressed | Compressed | | | | Fixed | Huffman | +-----------------------------------+------------------+------------------+------------------+ | Data (in KB) | num | num | num | | Percent savings | | num%| num%| | | | | | | Average Bytes per row | num | num | num | | Percent savings | | num%| num%| | | | | | | Data Pages needed | num | num | num | | Percent Data pages saved | | num%| num%| | | | | | | Dictionary pages required | num | num | num | | Rows scanned to build dictionary | | num | num | | Rows scanned to provide estimate | | num | num | | Dictionary Entries | | num | num | | | | | | | Total Pages (Dictionary + Data) | num | num | num | | Percent savings | | num%| num%| +-----------------------------------+------------------+------------------+------------------+
If DSN1COMP was run on with
PARM='COMPTYPE(HUFFMAN)', the DN1COMP utility report for a table space has the following format.DSN1940I DSN1COMP COMPRESSION REPORT Hardware support for Huffman compression is availablility-status +-----------------------------------+------------------+------------------+ | | Uncompressed | Compressed | | | | Huffman | +-----------------------------------+------------------+------------------+ | Data (in KB) | num | num | | Percent savings | | num%| | | | | | Average Bytes per row | num | num | | Percent savings | | num%| | | | | | Data Pages needed | num | num | | Percent Data pages saved | | num%| | | | | | Dictionary pages required | num | num | | Rows scanned to build dictionary | | num | | Rows scanned to provide estimate | | num | | Dictionary Entries | | num | | | | | | Total Pages (Dictionary + Data) | num | num | | Percent savings | | num%| +-----------------------------------+------------------+------------------+
In the following situations, the DN1COMP utility report for a table space has the following format.
- The COMPTYPE parameter was omitted on IBM z13® or earlier hardware
PARM='COMPTYPE(FIXED)'was specified.- A non UTS table space was specified
DSN1940I DSN1COMP COMPRESSION REPORT Hardware support for Huffman compression is availablility-status +-----------------------------------+------------------+------------------+ | | Uncompressed | Compressed | | | | Fixed | +-----------------------------------+------------------+------------------+ | Data (in KB) | num | num | | Percent savings | | num%| | | | | | Average Bytes per row | num | num | | Percent savings | | num%| | | | | | Data Pages needed | num | num | | Percent Data pages saved | | num%| | | | | | Dictionary pages required | num | num | | Rows scanned to build dictionary | | num | | Rows scanned to provide estimate | | num | | Dictionary Entries | | num | | | | | | Total Pages (Dictionary + Data) | num | num | | Percent savings | | num%| +-----------------------------------+------------------+------------------+
- Index report format
- The DN1COMP utility report for an index has the following format.
DSN1940I DSN1COMP COMPRESSION REPORT num Index Leaf Pages Processed num Keys Processed num Rids Processed num KB of Key Data Processed num KB of Compressed Keys Produced EVALUATION OF COMPRESSION WITH DIFFERENT INDEX PAGE SIZES: ---------------------------------------------- num K Page Buffer Size yields a num % Reduction in Index Leaf Page Space The Resulting Index would have approximately num % of the original index's Leaf Page Space No Bufferpool Space would be unused ---------------------------------------------- ---------------------------------------------- num K Page Buffer Size yields a num % Reduction in Index Leaf Page Space The Resulting Index would have approximately num % of the original index's Leaf Page Space num % of Bufferpool Space would be unused to ensure keys fit into compressed buffers ---------------------------------------------- - Uncompressed LOB table space format
-
The DSN1COMP utility report for an uncompressed LOB table space has the following format.
DSN1940I DSN1COMP COMPRESSION REPORT DSN1COMP run on uncompressed LOB table space LOB table space statistics --------------------------------------------------------- Number of LOBs num LOBs Minimum LOB size num KB Maximum LOB size num KB Average LOB size num KB LOB compression ratio --------------------------------------------------------- Total LOB data compressed num KB Total LOB data uncompressed num KB Percentage of KB saved num % Minimum System pages required num Pages Data pages needed for compressed LOB table space num Pages Data pages needed for uncompressed LOB table space num Pages Percentage of Data pages saved num % Current page size num KB EVALUATION OF COMPRESSION WITH DIFFERENT PAGE SIZES Note: System Pages may contain LOB data! --------------------------------------------------------- 4K page size: Minimum System pages required num Pages Additional Data pages needed for compressed LOBs num Pages Additional Data pages needed for uncompressed LOBs num Pages Data pages saved (not including system pages) num % 8K page size: Minimum System pages required num Pages Additional Data pages needed for compressed LOBs num Pages Additional Data pages needed for uncompressed LOBs num Pages Data pages saved (not including system pages) num % 16K page size: Minimum System pages required num Pages Additional Data pages needed for compressed LOBs num Pages Additional Data pages needed for uncompressed LOBs num Pages Data pages saved (not including system pages) num % 32K page size: Minimum System pages required num Pages Additional Data pages needed for compressed LOBs num Pages Additional Data pages needed for uncompressed LOBs num Pages Data pages saved (not including system pages) num %
- Compressed LOB table space format
-
The DSN1COMP utility report for a compressed LOB table space has the following format.
DSN1940I DSN1COMP COMPRESSION REPORT DSN1COMP run on compressed LOB table space LOB table space statistics --------------------------------------------------------- Number of LOBs num LOBs Minimum LOB size num KB Maximum LOB size num KB Average LOB size num KB Table space with compression (in KB) --------------------------------------------------------- Total uncompressed data num KB Total compressed data num KB Total LOB data num KB Table space if uncompressed (in KB) --------------------------------------------------------- Total uncompressed data num KB Total compressed data num KB Total LOB data num KB LOB compression ratio --------------------------------------------------------- Total LOB data compressed num KB Total LOB data uncompressed num KB Percentage of KB saved num % Minimum System pages required num Pages Data pages needed for compressed LOB table space num Pages Data pages needed for uncompressed LOB table space num Pages Percentage of Data pages saved num % Current page size num KB EVALUATION OF COMPRESSION WITH DIFFERENT PAGE SIZES Note: System Pages may contain LOB data! --------------------------------------------------------- 4K page size: Minimum System pages required num Pages Additional Data pages needed for compressed LOBs num Pages Additional Data pages needed for uncompressed LOBs num Pages Data pages saved (not including system pages) num % 8K page size: Minimum System pages required num Pages Additional Data pages needed for compressed LOBs num Pages Additional Data pages needed for uncompressed LOBs num Pages Data pages saved (not including system pages) num % 16K page size: Minimum System pages required num Pages Additional Data pages needed for compressed LOBs num Pages Additional Data pages needed for uncompressed LOBs num Pages Data pages saved (not including system pages) num % 32K page size: Minimum System pages required num Pages Additional Data pages needed for compressed LOBs num Pages Additional Data pages needed for uncompressed LOBs num Pages Data pages saved (not including system pages) num %
System action
The utility completed successfully.
Severity
0 (informational)