Modeling a Lifecycle

To correctly model a lifecycle you must define the lifecycle and its phases, and then associate your tables to it.

1. Create a lifecycle in any of the following ways:

   • Select Model > Lifecycles (or Database > Information Lifecycle Management > List of Lifecycles) to access the List of Lifecycles, and click the Add a Row tool.

   • Right-click the model in the Browser, and select New > Lifecycle. Note that lifecycles can only be created at the model level and not within packages.

2. Click the Properties tool to open the lifecycle property sheet and specify a name for the lifecycle.
3. Click the Definition tab, and select the policy type:
   • Age-based - Data moves through the lifecycle in named partitions, based on the time since the data was created. Specify a Start date and the Total retention period (the length of time covered by the lifecycle).
   • Access-based - Tables move through the lifecycle based on the time since the table was last accessed. Specify a Total retention period, which is treated as the minimum total period of time that a table's data must remain in the lifecycle.
4. Click the Create Phase tool to create as many phases as you need. Lifecycles often contain three phases to manage the movement of data from high performance, through nearline, to historical storage.
   Note: Your phase will display a yellow warning overlay until it is completely defined.
5. Click on each phase in turn to open its property sheet (see Phase Properties). Specify a name, retention period (or, for access-based lifecycles, idle period) and tablespace to represent the physical storage in which the data is stored during this phase.

   For age-based lifecycles, you can assign data from an external database to the first phase of your lifecycle and have that data loaded to your warehouse database for the second phase (see Archiving Data From External Databases).

6. Open the property sheet for each of your tablespaces (see Tablespace and Storage Properties) and enter any appropriate properties, including a value for the cost per GB to be used when calculating cost savings.
   When you have completed the definition of your phases and tablespaces, return to the lifecycle property sheet and verify that the warning overlays on the phase buttons are no longer present.
7. [age-based lifecycles] Enter a partition range to specify the length of time covered by each table partition governed by the lifecycle. For example, a partition range of one month means that each partition will contain one month's data.
8. In the Managed tables groupbox, select the tables you want to associate with the lifecycle. For each table, specify the start date on which you want it to become subject to the lifecycle, and enter an estimate for the initial number of rows and a percentage growth rate to permit the calculation of cost savings.
9. [age-based lifecycles] You must, for each table, specify a column with a date datatype as the partition key used to determine to which partition a row must be assigned. The partition key can alternately be assigned on the Sybase IQ tab of the table property sheets.
10. [optional] Select the Cost savings analysis checkbox and then click the Refresh Cost Savings Analysis tool to display a summary of the cost savings to be obtained by managing your data with the lifecycle.

    You can also view the detail of the cost savings by year for a single table on the Lifecyle tab of the table property sheet (see Table Properties).

    Note: If you intend to model multiple lifecycles, and/or want to confirm that all of your tables are associated with a lifecycle, you may find it useful to visualize these associations in the form of a dependency matrix. To view the Lifecycle/Table Matrix, select Database > Information Lifecycle Management > View Lifecycle/Table Matrix.

• Generating Data Archiving Scripts to Implement your Lifecycle
  Once you have modeled your lifecycles, you can instruct PowerDesigner to generate scripts to automate the creation, movement, and purging of data through your lifecycle phases.