LOADPLUS processing phases

UTILINIT

During this phase, LOADPLUS completes the following processes:

• Initializes the job
• Reads, parses, and verifies the LOAD command
• Performs Db2 catalog lookup
• If you enabled automated file size estimation, estimates input file size
• If any referenced object is VCAT-defined, verify the commands in the SYSIDCIN data set

DSNUTILB

LOADPLUS executes this phase only when the type of load that you are running requires it. During this phase, LOADPLUS passes processing to DSNUTILB. This phase takes the place of the LOADPLUS PRELOAD, LOAD, and COMBINED phases. Additionally, this phase performs some of the tasks that the UTILTERM phase normally performs, such as updating statistics.

For more information about the types of load jobs that require this phase, see  Load jobs that invoke DSNUTILB.

ANALYZE

During this optional phase, LOADPLUS completes the following processes:

• Analyzes the objects that are being loaded
• Optionally produces statistics to help determine data set sizes for allocating those data sets

LOADPLUS executes this phase when dynamic data set allocation is active or when you specify the ANALYZE command option. LOADPLUS uses information from this phase to optimize the load process.

PRELOAD

During this phase, LOADPLUS reads data from the input data sets. Additionally, LOADPLUS completes the following processes:

• Converts data as needed and verifies that the data is correct
• Builds Db2 rows in the SORTOUT data set
• Builds index information in the SYSUT1 data set
• Writes input records that are in error to the SYSDISC discard data set
• Builds the compression dictionary and compresses the data rows
• Invokes the BMCSORT component when applicable
• Reads the indexes and table space of the table or partition being loaded, if you are loading rows into tables or partitions that already contain data

The SYSREC and SYSDISC data sets are freed at the end of this phase, and you should not specify FREE=CLOSE for these data sets.

LOAD

During this phase, LOADPLUS completes the following processes:

• Redefines the VSAM data sets if the value of the REDEFINE option is YES
• Reads the rows from the SORTOUT and SYSUT1 data sets
• Loads the data into the table space and indexes
• Adds partitions for partition-by-growth table spaces if required (SHRLEVEL NONE)
• Invokes BMCSORT for indexes that are not sorted in the PRELOAD phase
• Builds or updates indexes
• Creates any requested copies and registers them with the Db2 catalog

COMBINED

This phase combines all functions of the PRELOAD and LOAD phases into a single processing phase. In most cases, the COMBINED phase avoids the intermediate steps of writing to the SORTOUT and SYSUT1 data sets; instead, LOADPLUS either writes data directly to the table space and index space or sends data directly to the High-speed Apply Engine product to be inserted into the table space and index space.

UTILTERM

During this phase, LOADPLUS completes the following cleanup tasks:

• Sets the pending status of all affected tables and table spaces
• Updates the BMCHIST table
• Updates the DASD MANAGER PLUS database statistics tables
• Updates the Db2 catalog statistics
• Updates the Db2 real-time statistics tables
• Adds partitions for partition-by-growth table spaces if required (SHRLEVEL REFERENCE or SHRLEVEL CHANGE)
• Performs the FASTSWITCH or rename operations that are associated with the staging data sets for SHRLEVEL CHANGE (except an SQLAPPLY load) and SHRLEVEL REFERENCE
• Performs a clone exchange, if requested
• Cleans up the BMCUTIL, BMCUTIL2, and BMCSYNC tables

LOADPLUS executes only part of this phase when invoking DSNUTILB.

All phases

During all phases except the DSNUTILB phase, LOADPLUS updates the BMCUTIL, BMCUTIL2, and BMCSYNC DB2 tables.