Module planner 

Developer: s4gor Github: https://github.com/s4gor

Migration planning

The planner takes a schema diff and creates an executable migration plan. The plan is a sequence of operations that will transform the current schema into the target schema.

Design Rationale

Separating planning from execution allows:

• Dry-run mode to show what would happen
• Validation of plans before execution
• Different planning strategies (safe ordering, dependency resolution)
• Testing plans without executing them

Structs

CheckConstraintDefinition

Check constraint definition

ColumnChanges

Column changes for modify operations

ColumnDefinition

Column definition for migration operations

DefaultChange

Default value change (old and new)

ForeignKeyDefinition

Foreign key definition

IndexDefinition

Index definition

MigrationPlan

A migration plan containing the sequence of operations to execute

MigrationStep

A single step in a migration plan

PrimaryKeyDefinition

Primary key definition

TypeChange

Type change (old and new)

UniqueConstraintDefinition

Unique constraint definition

Enums

MigrationOperation

A single migration operation

Traits

Planner

Trait for planning migrations