Skip to main content

Using the + prefix

The + prefix is a dbt syntax feature, introduced in dbt v0.17.0, which helps disambiguate between resource paths and configs in dbt_project.yml files.

It is not compatible with dbt_project.yml files that use config-version 1.

For example:

dbt_project.yml
name: jaffle_shop
config-version: 2

...

models:
  +materialized: view
  jaffle_shop:
    marts:
      +materialized: table

Throughout this documentation, we've tried to be consistent in using the + prefix in dbt_project.yml files.

However, the leading + is in fact only required when you need to disambiguate between resource paths and configs, for example when:

  • A config accepts a dictionary as its inputs, for example, the persist_docs config.
  • Or, a config shares a key with part of a resource path, for example, if you had a directory of models named tags.
dbt_project.yml
name: jaffle_shop
config-version: 2

...

models:
  +persist_docs: # this config is a dictionary, so needs a + prefix
    relation: true
    columns: true

  jaffle_shop:
    schema: my_schema # a plus prefix is optional here
    +tags: # this is the tag config
      - "hello"
    tags: # whereas this is the tag resource path
      # The below config applies to models in the
      # models/tags/ directory.
      # Note: you don't _need_ a leading + here,
      # but it wouldn't hurt.
      materialized: view


When adding configs in dbt_project.yml, it doesn't hurt to use the + prefix, so we recommend you use it always.

Note: This use of the + prefix, in dbt_project.yml, is distinct from the use of + to control config merge behavior (clobber vs. add) in other config settings (specific resource .yml and .sql files). Currently, the only config which supports + for controlling config merge behavior is grants.

0