HANDLER

In the Ultra Transcenders books

DBX-DEP

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

Terms in this definition

• Unity Catalog

  Azure Databricks' governance solution covering both data and AI in one place, with centralised permissions, auditing, data discovery and lineage.

• UDF

  Custom logic written in JavaScript and registered with a Cosmos DB container, callable only from queries. Calling one raises the request unit charge.

• FUNCTION

  Registered models count as functions in Unity Catalog, so this securable type governs them too: access is given through GRANT ... ON FUNCTION, and REST calls pass FUNCTION as securable_type.

• CREATE FUNCTION

  Adds a table function, or a Python or SQL UDF, to Unity Catalog so that it falls under governance like other objects. Doing so takes the relevant privilege on the schema.

• Iterator

  A DAX function like SUMX that steps through a table one row at a time, evaluating an expression in row context, and then aggregates what it gets.

Related terms

• At-least-once delivery

  A guarantee that every message or change arrives, though possibly more than once, for instance when a handler fails or a lock is lost. Code that processes it therefore needs to be idempotent.

• PARAMETER STYLE PANDAS

  Turns a Unity Catalog Python UDF into a batch function when used in CREATE FUNCTION. Its HANDLER receives an iterator of pandas.Series, and the output row count has to equal the input row count.