Pre-requisites Before Mapping Starts

Do not open the MID until the following artefacts have been collected from the client. Attempting to map without these leads to guesswork and rework.

Table 1. Pre-requisites Checklist
Pre-requisite Why it is needed Collected?
Source system inventory (list of all systems in scope) Understand the landscape before selecting scope
Table and column list (DDL or schema export) Provides the raw mapping surface
Data dictionary / business glossary Gives meaning to column names — essential for semantic mapping
Primary and business keys for each table Required to determine grain and set up LDZ natural keys
Sample data (de-identified, at least 100–500 rows) Validates data types, nullability, and code values
Relationship / ER documentation Identifies which tables link and how — needed for relationship entity mapping
Refresh frequency and CDC / delta logic availability Drives LDZ load strategy (truncate, delta, CDC)
Source-to-source join logic (if needed) Some LDZ targets require joining two source tables
PII / sensitive field register Ensures encryption, masking, and compliance flags are applied
Mandatory business rules and derivations Transformation logic cannot be written without these
Source code sets and reference values Code conversion tables (e.g., "M/F" vs "MALE/FEMALE") needed upfront