2) Input

This section defines the database change request that SchemaFlow will process. Think of it as the compact ticket, issue, or message a data team might receive before turning the request into implementation details.

The default request asks the workflow to:

1. Add LOYALTY_TIER VARCHAR(20) to ODS.ODS_CUSTOMER_PROFILE.
2. Treat the new column as nullable.
3. Backfill from CORE.DIM_CUSTOMER.
4. Join on CUSTOMER_ID.
5. Filter the source to current records with IS_CURRENT=true.
6. Add a non-unique index on (CUSTOMER_ID, LOYALTY_TIER).

This input is intentionally compact but rich enough to exercise the full workflow:

• parsing target schema and table
• extracting column name, type, and nullability
• recognizing backfill requirements
• recognizing index requirements
• generating multi-layer SQL
• running validation checks for expected table, column, and SQL actions

CHANGE_TEXT = """Add LOYALTY_TIER VARCHAR(20) to ODS.ODS_CUSTOMER_PROFILE as nullable.
Backfill from CORE.DIM_CUSTOMER on CUSTOMER_ID where IS_CURRENT=true.
Add a non-unique index on (CUSTOMER_ID, LOYALTY_TIER)."""
print(CHANGE_TEXT)