 | Finalize Physical Data Model |
| Perform Physical Data Migration Process |
| Gain Physical Design & Migration Plan Sign-Off< |
Depending on the methodology and I-CASE tool set, physical database design is typically completed during a technical design phase. While this is a data administration task, recognition of current data redundancies and inconsistencies should help deliver a better physical design. It also streamlines the migration to the new data architecture.
This task also includes a data migration planning and execution step that assists in finalizing the new physical database.
Specific task objectives include:
· Finalizing a target physical database design
· Defining the physical data migration and purification process
The entrance criteria for the physical data analysis and migration task are listed below.
· Environmental analysis of Inventory/Analysis
· Subject area/entity type analysis of Inventory/Analysis
· Data definition analysis of Inventory/Analysis
· Logical data analysis task of Transformation
· Scenario-based completion of prior Transformation tasks leading to development of a new physical database
· Data definition rationalization and literal externalization Positioning tasks
Optional - based on availability:
· Population of LTM repository model as completed in process hierarchy/dependency task
The personnel and skill requirements necessary to meet the physical data analysis and migration task are identified below.
· Data Modeling Expert
- Physical database designer
· Current Systems Expert
- Knowledge of existing system physical data environment
- Knowledge of current functional data utilization
· Repository Administrator
- Ability to access LTM repository
· Data Administrator/DBA
- Ability to identify primary data structures that cross application functional boundaries
· Target System Functional Expert
- Knowledge of target functional data requirements
· User Requirements Analyst
- Authority to sign off on data model and migration plan
The system components and related inputs required to initiate and complete the physical data analysis and migration task are listed below.
· Environmental cross reference results showing links between physical data files and databases and current system modules
· Data defect lists or reports for current data stores
· Systems having undergone data name rationalization and literal externalization
· System flows (DFD) from architecture analysis showing physical data structures and links to current executables
· Logical (normalized) data model for target architecture
Optional - based on availability:
· Population of LTM repository model as completed in entrance criteria tasks
Technologies supporting the physical data analysis and migration task include physical data design, physical data analyzer, data migration, open systems repository, cataloging, and word processing tools. These tools are used to represent information as required by this task.
Physical Data Design Tools
Tool support for this process includes some of the products used to develop prior logical data models. Key features include ability to accept logical data model and physical data volume requirements as input to development of relational database tables.
Physical data analyzer
Within this task, the role of the physical data analyzer is to automatically scan selected data and produce a sampling of defective data.
There are three common methods for determining defective data: comparison of the data to user-defined rules, comparison of the data to system definitions (either hard-coded in the source or defined in the dictionary) and analysis of the data alone to discover inherent rules and dependencies.
Some tools review all the data in the selected data stores, while others sample the data in some pre-defined or random pattern. Some physical data analyzers can also produce management reports on the quality of the data. Features should include ability to provide physical data value sampling.
Data migration tool
Within this task, the role of the data migration tool is to automate the process of converting data values in a physical data store. This may involve mapping data from multiple existing data stores into a single target store, inserting new data values based on a default or some other user criteria, converting existing values to a new length or attribute type, or moving data to a new platform.
To accomplish this, data migration tools must have the ability to analyze, manipulate and convert data to user specification. The tool should be able to utilize either a data dictionary, a repository or a set of user-defined specifications, or some combination of the three, to provide a source definition and a target definition for the data to be converted. In addition, bench marking features or strategies are essential to accurate conversion processing.
Open system repository
A repository provides an important, yet optional, capability to link business areas, systems and components using the legacy transition meta-model. In this task, repository is used to trace current to current and current to target repository objects to establish data migration plan.
Cataloging tool
A cataloging tool provides the user with the ability to establish libraries and data sets on the system catalog with specific characteristics including location, read/write capability, file duration, etc. In this task, cataloging tool is used to enter new data store names in the system catalog.
Word processor
In this task, the word processor is used to finalize the data migration plan.
The physical data analysis and migration task is comprised of the following task steps:
Finalize Physical Data Model Perform Physical Data Migration Process Gain Physical Design & Migration Plan Sign-Off<