This document provides an overview of reusable definitions in Hackolade: - Definitions can be created at the entity, model, and external levels to increase productivity, consistency, and data quality - Definitions can be converted from objects and referenced in multiple places - The Model Definitions tab allows maintaining and viewing where definitions are used - JSON Schema previews show how definitions are resolved and converted to internal structures - Definitions can be extended or replaced as needed, and referenced from external files

1. Hackolade Tutorial
Tutorial Expert – Add Reusable Definitions
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2. Why reusable definitions?
• To increase productivity
• To increase convenience
• To increase consistency
• To achieve higher data quality
• To achieve higher degrees of governance
• To stitch together different domain models into an umbrella model
• Create and maintain object definitions that can be reused in multiple
places
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3. About definitions
• At 3 levels:
• Internal definitions: at the entity level
• Ensure JSON schema compatibility
• Noted as (i) in the ERD view
• Model definitions: at the model level
• Noted as (m) in the ERD view
• Different names in some targets:
• “User Defined Types” in some relational targets
• “Definitions” in Swagger
• “Components” in OpenAPI
• External definitions: across data models
• Noted as (e) in the ERD view
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4. Convert an object into a model definition
• ERD and schema tree view updated
• Model definitions tab is updated
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5. Reference an existing definition
• Via context menu
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6. Maintain definitions
• In Model Definitions tab: changes immediately reflected wherever
referenced
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7. JSON Schema Preview
• Using $ref syntax
• Referenced, Resolved and Internal
views
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8. Resolved and Internal view
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Resolved: the $ref pointer is replaced by the actual
structure of the definition
Internal: the model definition is converted into an internal
definition for the entity, according to the JSON Schema standard

9. Deviate from a definition
• By creating a 2nd definition that
matches new needs
• By replacing the definition with
attributes
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10. Display Where-Used
• When definitions are used in
multiple places
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11. External definitions
• External files:
• Hackolade data model
• JSON schema
• Swagger/OpenAPI specs
• Can be referenced in whole or in
part
• Note choice of path!
• Avoid too many recursive
references!
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12. Reading material
• See Hackolade online documentation
• The Hackolade Blog
• This excellent new book:
MongoDB Data Modeling & Schema Design
• Many of the principles in the book are related to query
driven modeling based on access patterns!
• Hackolade’s on social media: LinkedIn page, Twitter page
• Download Hackolade studio for free
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13. Questions?
Answers!
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