Preparing Schemas for Migration - Teradata Schema Workbench

Teradata Schema Workbench User Guide

Product
Teradata Schema Workbench
Release Number
16.20
16.10
15.10
Published
June 2015
Language
English (United States)
Last Update
2018-05-25
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B035-4106
Product Category
Teradata Tools and Utilities
Prepare the schema to minimize issues that could arise during migration. If you have schemas created in Teradata Schema Workbench 13.10 but do not have a Teradata Schema Workbench 13.10 installation, go to Migrating a Schema. For instructions on how to access the Teradata Schema Workbench User Guide for 13.10, see Additional Information.
Ensure you are using the latest version of Teradata Schema Workbench 13.10 before beginning the procedure.
  1. In Teradata Schema Workbench 13.10, open a schema to prepare for migration to Teradata Schema Workbench 14.00 and above.
  2. Remove any instances of the following from the schema:
    • Cycles

      A cycle is a circular reference wherein a join path from one table refers to a table, which through a series of subsequent join references, returns to the original table. For example, Table A refers to Table B, Table B refers to Table C, and Table C refers to Table A. The Schema Migration Assistant does not migrate tables with cycles, because they cause invalid star or snowflake schema.

    • Multiple hierarchies in the same dimension that use different leaf members tables

      This means all hierarchies in the dimension must join the fact table from the same dimension table. The lowest level in a hierarchy must join to the fact table.

  3. Update dimension names (schema and cube-scoped) so no two dimension names match. The automatic naming format is originalName_cubeName. For example, a measure Store Sales in cube OMart4 would rename to Store Sales_ OMart4.
  4. Update all measure names so that no two measure names in the schema are the same.
  5. Update calculated members and calculated measures referring to renamed dimensions or measures.
  6. Validate the schema. See Schema Validation.
  7. Save the schema as an external file. See Saving a Schema to the File System.
  8. Complete the instructions in Migrating a Schema.