Constraint

In the Ultra Transcenders books

2V0-13.25

Each book explains Constraint in context, with comparison tables and the common traps.

Terms in this definition

• Set

  Secret permission in Key Vault for writing secrets; some older material refers to it as Create.

• LIMIT

  Caps how many rows a SQL query gives back. Don't treat what you get as random or representative.

• Budget

  A spending threshold you set in Cost Management for a management group, subscription or resource group. Alerts go out as real or forecast costs approach it, yet hitting the figure never halts any resource; wiring it to an action group lets automation react.

• HAVING

  Applies a condition to groups produced by GROUP BY, often on an aggregate such as SUM(). WHERE works earlier, on individual rows before they are grouped.

• Gap

  What differs between one state and another; usually this means the difference from the baseline architecture to the target one.

• Risk

  As ISO 31000 puts it, how uncertainty affects objectives; that effect can be good or bad.

Related terms

• AFTER trigger

  A DML trigger that fires once the statement that caused it, and its constraint checks, have completed successfully, still within that transaction. It can only be defined on tables; to replace an action, or to work on a view, use an INSTEAD OF trigger.

• CHECK constraint

  Added via ALTER TABLE ... ADD CONSTRAINT name CHECK (expr), this Delta rule requires a deterministic Boolean expression to be true for each row. Current rows are validated before it takes effect, and writes that would break it fail.

• DEFAULT constraint

  A constraint that fills in a column, for instance with a fixed value or SYSDATETIMEOFFSET(), whenever an INSERT leaves that column out. It has no effect on UPDATE statements.

• Demographic parity

  A fairness constraint that mitigates allocation harms by asking for comparable selection rates in every sensitive group.

• Design decision

  Explains, for one choice made in a design, the requirement or constraint it serves, the reasoning, the consequences and what was actually decided. VCF's design guide writes up its own recommendations and requirements using that same pattern of ID, justification and implication.

• Design requirement

  A VCF design element that is essential for VCF to work and therefore cannot be departed from; within a customer design it acts as a constraint, not a choice.

• Equalized odds

  Fairness constraint for binary classifiers asking that sensitive groups see comparable false-positive and true-positive rates.

• Expectations

  Optional data quality rules declared with CONSTRAINT ... EXPECT on the tables and views a pipeline defines. Each incoming record is checked; on failure the pipeline can just record a warning (the default), discard the record or halt the update, and the results are logged.