Version 14.0 › CA Datacom Tools Products › New Features and Enhancements › MUF LXX Format Options

MUF LXX Format Options

The MUF LXX format options feature is a performance enhancement that allows MUF to process more maintenance requests per second while reducing the "Total Cost of Ownership." This enhancement reduces the number of bytes stored with selected log records, thus reducing the number of bytes written to the LXX Data Set. Less bytes to write allows for less I/O, which results in better performance.

The LXX is used for temporary storage of data changes and control information. The size of the LXX should be large enough to contain all active transactions. The LXX should also have room to allow spilling to a Recovery File (RXX) to complete without the log becoming full.

Note: For most users, this feature can simply be turned on after reviewing the specific options. Much more information is provided to explain what the specific savings are and what to expect than is needed by most users.

LXX-Related MUF Startup Options Changes

A change that is not optional in Version 14.0 has to do with the format of log records that are subject to 'default' processing as follows:

• During an ADDIT, fields defined with a default that are not part of the element list or that are set with FORCEADD are added with a special element name that starts with a dash and percent sign (-%).
• During an UPDAT, a column with FORCEUPD has an element added similarly to that described for ADDIT, except that for UPDAT, starting with Version 14.0, the full record is logged with a special element name that starts with a dash and a pound-sign (-#).

Following are MUF startup option changes related to Version 14.0 changes to the LXX record format.

• LOG_RECORD_FORMAT
• LOG_RECORD_USER_CMPRS
• LOG_RECORD_UPDAT_SIZE
• LOG_RECORD_ENCRYPT

Details of the options are as follows:

• For tables that are not compressed (and user compressed with LOG_RECORD_USER_CMPRS NO):
  • ADDIT - The smaller of the Work Area plus internal element list or record size. For example, if the element list represents the full record as is most common, the element list of 11+ bytes is excluded from the log and is therefore a savings.
  • DELET - No change.
  • UPDAT - The before record is unchanged. The after is the smaller of the user Work Area plus internal element list or record size or LOG-RECORD_UPDAT_SIZE Work Area plus its internal element list.
• For tables that are variable (DBVVRPR):
  • ADDIT - The element list is removed (the Work Area is the full record to the user specified size). This saves 11+ bytes.
  • DELET - No change.
  • UPDAT - The element list is removed (the Work Area is the full record to the user specified size). This saves 11+ bytes.
• For tables that are CA Datacom/DB-compressed (and user compressed with LOG_RECORD_USER_CMPRS YES):
  • ADDIT - The smaller of the Work Area plus internal element list or record size or compressed record size (+16 if user compressed). Except if a table is encrypted and LOG_RECORD_ENCRYPT YES is set, where it takes precedence, and the compressed record or full record are selected.
  • DELET - The smaller of the record size or the compressed record size (+16 if user compressed). Except if a table is encrypted and LOG_RECORD_ENCRYPT YES is set, where it takes precedence, and the compressed record or full record are selected.
  • UPDAT - The before record is the smaller of the record size or the compressed record size (+16 if user compressed). The after is the smaller of the user Work Area plus internal element list or record size or compressed record size (+16 if user compressed) or LOG-RECORD_UPDAT_SIZE Work Area plus its internal element list. Except if a table is encrypted and LOG_RECORD_ENCRYPT YES is set, where it takes precedence, and the compressed record or full record are selected.