Seed Data
Initial content created programmatically to make an empty system usable or demonstrable.
Seed data is content generated to populate a fresh environment: an administrative account, reference data a system cannot function without, and demonstration content that makes the product show what it does.
It divides into two kinds with different requirements. Essential seeds are required for the system to work and belong to the deployment path, which means they must be idempotent and safe to run against a database that may already have them. Demonstration seeds exist for development and sales and can be as elaborate as anyone likes, provided they never run in production.
Two lessons repeat.
Seed content is real content for review purposes. Nobody reviews it as such, so errors in it live a long time. Descriptive text written from an intended image rather than the actual one passes every automated check — a type checker sees a string, a request returns success for any valid identifier, and an accessibility scan verifies only that alternative text exists, never that it describes anything. The only check is looking.
Seeds encode a data model that will change. Content authored against an earlier model is not portable to a later one by copying; it is re-authoring. Treating a large seed as a migratable asset underestimates the work considerably.
See also13
Database Migration
A versioned, ordered change to a database schema, applied once and recorded.
Data & Content20 connections
Test Fixture
The prepared data or state a test runs against.
Testing & Verification16 connections
Idempotence
The property that performing an operation twice has the same effect as performing it once.
Systems & Tooling34 connections
Relational Database
Data organized as tables with declared relationships, queried declaratively and guarded by constraints.
Data & Content21 connections
Write-Ahead Logging
Recording the intent of a change durably before applying it, so a crash can be recovered.
Computation & Algorithms20 connections
Hash Table
A key-value structure that uses a digest of the key to index an array of buckets.
Computation & Algorithms23 connections
Accessibility
Designing so that people with disabilities can use a thing, and the standards that make it checkable.
Design & Interface44 connections
Determinism
The property that identical inputs produce identical outputs, and the foundation of caching and verification.
Systems & Tooling61 connections
Lorem Ipsum
The scrambled Latin filler typesetters and designers use to show a layout before the real words exist, useful for judging type and dangerous because it hides what real content will do to the design.
Design & Interface6 connections
Foreign Key
A column that points at a row in another table, with the database refusing any change that would leave the pointer dangling.
Data & Content11 connections
Empty State
What an interface shows when there is nothing to show yet, a screen often designed last that is many people's first impression.
Design & Interface11 connections
Test Data Builder
Helpers that build valid test objects from sensible defaults so each test states only the fields it cares about, and the Object Mother pattern they grew out of.
Testing & Verification9 connections
CSV
The plain-text table format of rows separated by line breaks and fields separated by commas, universal and simple until quoting, encoding, and spreadsheets get involved.
Data & Content7 connections
Linked from10
- Database MigrationData & Content
A versioned, ordered change to a database schema, applied once and recorded.
- Empty StateDesign & Interface
What an interface shows when there is nothing to show yet, a screen often designed last that is many people's first impression.
- Foreign KeyData & Content
A column that points at a row in another table, with the database refusing any change that would leave the pointer dangling.
- IdempotenceSystems & Tooling
The property that performing an operation twice has the same effect as performing it once.
- Lorem IpsumDesign & Interface
The scrambled Latin filler typesetters and designers use to show a layout before the real words exist, useful for judging type and dangerous because it hides what real content will do to the design.
- Personal DataData & Content
Any information that relates to an identifiable person, why it is broader than names and emails, and the engineering habits that privacy law now expects.
- Relational DatabaseData & Content
Data organized as tables with declared relationships, queried declaratively and guarded by constraints.
- Test Data BuilderTesting & Verification
Helpers that build valid test objects from sensible defaults so each test states only the fields it cares about, and the Object Mother pattern they grew out of.
- Test FixtureTesting & Verification
The prepared data or state a test runs against.
- Write-Ahead LoggingComputation & Algorithms
Recording the intent of a change durably before applying it, so a crash can be recovered.