Defining the number of partitions by specifying high keys

After DBDs are selected, you can define the number of database partitions you want to have by specifying high keys for the partitions.

About this task

The number of partitions will be the number of high keys you specify. You must select partition boundaries for all participating databases, including secondary indexes. You need not specify the keys in sequence. The highest key defined is replaced as x'FF'.

The index record size increases significantly because of the increase in the pointer size from 4 to 28 and the addition of the root segment key.

Procedure

  1. On the Primary DBD Partitioning Rules panel, select option 4 Specify High Keys.
    Figure 1. Primary DBD Partitioning Rules panel
    ------------------------------ IMS HALDB Toolkit -----------------------------
    Command ===>                                                                  
                                                                                  
                         Primary DBD Partitioning Rules                           
                                                                                  
                                                                                  
      Partitions:        3     1  Fixed Number of Partitions     1                
                               2  Fixed Partition Size (MB)      2048             
                               3  Ask during Conversion                           
                               4  Specify High Keys                               
                                                                                  
      PDB Conversion:    3     1  Use existing Keys or Partitions                 
                               2  Create new Partition boundaries                 
                               3  Ask during Conversion                           
                                                                                  
      Additional Partitioning Layouts to be created?                              
                         2     1  Yes                                             
                               2  No, use the one created during Collect          
                                                                                  
      Combine Database records:                                                   
                         5000   (number of database records)                      
    
    
    

    The Specify Partition Keystrings panel is displayed.

  2. To specify keys, select option 1 or 2 depending on whether you want character or hex format.
    Figure 2. Specify Partition Keystrings panel
    ------------------------------ IMS HALDB Toolkit -----------------------------
    Command ===>
    
                       Specify Partition Keystrings
    
                         Select
                         1  Enter keystrings in character format
                         2  Enter keystrings in hex format
                         3  Provide dataset
                            Member              (if dataset is partitioned)
    -------------------------------------------------------------------------
      

  3. Optional: Select option 1 and the Specify Partition Keystrings Character Keystrings only panel is displayed.

    Enter one key at a time; or, if you have a file containing the keys, you can use it here.

    The file must have as many records as the number of keys you want, the keys must be the first position of the record, and the file must have fixed record length.
    Figure 3. Specify Partition Keystrings (character) panel
    ------------------------------ IMS HALDB Toolkit -----------------------------
    Command ===>
    
                       Specify Partition Keystrings
                         Character Keystrings only
    
                         Max key length:  0
                         No. of keys   :  0
    
    Key:  0101
    
       Specify 'FF' for high value key
    -------------------------------------------------------------------------
      

  4. When you have entered all keys, press the End key.
    The Keystrings for xxxxx panel displays all keys that were entered.
  5. To change this list, select option D, C, or I.
  6. Press the End key to begin processing, when the list is final.
  7. Verify partitioning results. You can view results using the output list from the data collector.
    Figure 4. Displaying high keys
    ------------------------------ IMS HALDB Toolkit ------------------Row 1 of 3
    Command ===>
    
                       Keystrings for DBD HD02
    
                  Selections:  "D" for DELETE          Key Length:  0
                               "C" for CHANGE          Key Offset:  0
                               "I" for INSERT
    1
    S             Key value
    -------------------------------------------------------------------------
           Char:  0101
           Hex :  F0F1F0F1
     
           Char:  66
           Hex :  F6F6
    
           Char:  .
           Hex :  FF
    ****************************** Bottom of data ****************************