Control / subflow · All operations

Define a reusable macro or function

A variant of Call a reusable workflow

Write a parameterised macro or function once and call it from many queries or flows.

Status

In arcform

Not built yet

arcform does not do this yet; it would live in how a Protocol runs. Its place on the roadmap

What other tools call it

Meridian's classification; an independent blind rating agreed on 95.7% of 324 rows (variant, version 3).

AWS Glue (1)
  • Custom visual transformsread 2026-09-27

    User-built transforms, uploaded to Amazon S3, that then appear as nodes in the visual editor

Azure Data Factory (1)
  • User defined functionsread 2026-09-27

    Reusable custom expression functions, kept in libraries and shared between data flows

Bruin (1)
  • Macros (user-defined)read 2026-09-27

    User Jinja macros in a macros/ directory, loaded automatically and called from SQL assets

DuckDB (1)
  • CREATE MACROread 2026-09-27

    Define a reusable scalar or table macro in SQL

Polars (2)
  • DataFrame.piperead 2026-09-27

    Pass the frame through a user function so custom steps chain like methods

  • LazyFrame.pipe_with_schemaread 2026-09-27

    Pass the lazy frame and its resolved schema to a user function at planning time

Power Query M (1)
  • Function valuesread 2026-09-27

    6 functions: Function.Invoke, Function.InvokeAfter, Function.From, Function.ScalarVector, Function.IsDataSource

RapidMiner Studio (2)
  • Custom Subprocessread 2026-09-27

    Define a custom operator that exposes subprocesses to its user

  • Metadata Helperread 2026-09-27

    Define the output metadata of a custom operator via a subprocess, leaving data unchanged

SQLMesh (1)
  • Jinja macrosread 2026-09-27

    Jinja templating and user macro functions as the alternative macro system

Background

In DuckDB, the CREATE MACRO statement defines a named, callable Structured Query Language (SQL) expression as a database schema object.[1] A parameterised macro is able to insert given objects into its expansion, which gives the macro some of the power of a function.[2] In Bruin, macros are reusable pieces of Jinja code that define SQL patterns once for use throughout a pipeline.[3]

When to use it

In Azure Data Factory (ADF), logic built repeatedly in expressions across multiple mapping data flows is a good opportunity for a user defined function.[4] In Bruin, simple patterns might not need a macro, and some complex macros might impact query performance.[3]

In DuckDB, a macro parameter's default value is in principle evaluated when the macro is defined, not when it runs.[1] In DuckDB, an = in a macro call is read as a comparison rather than a named parameter, so named parameters are passed with :=.[1] In DuckDB, defining a recursive macro is not supported.[1] In Bruin, SQL comments do not prevent Jinja from processing macros, so a macro call inside a comment still executes.[3] In ADF, a user defined function cannot refer to another user defined function.[4]

The method

Applying a macro to an input is known as macro expansion.[2] In DuckDB, a macro call is expanded: the macro is replaced with its expression, and the parameters in it are replaced with the supplied arguments.[1] In DuckDB, a scalar macro evaluates to a scalar value, while a table macro returns a tabular result and acts essentially as a table function.[1] In DuckDB, a macro can be overloaded on the types or the number of its parameters, with every implementation defined in the same CREATE MACRO statement.[1]

In Bruin, all macros defined in the pipeline's macros/ folder are loaded automatically and can be used anywhere without explicit imports.[3] In Bruin, the bruin render command shows exactly what macros generate.[3] In ADF, user defined functions live in a collection called a data flow library, and each can take zero or more arguments.[4]

Compared with the alternatives

In DuckDB, the CREATE FUNCTION statement is an alias for CREATE MACRO.[1]

Sources

  1. [1]CREATE MACRO Statement – DuckDBdocumentation
  2. [2]Macro (computer science)secondary source
  3. [3]Macros | Bruin CLIdocumentation
  4. [4]User defined functions in mapping data flows - Azure Data Factory & Azure Synapse | Microsoft Learndocumentation