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 only compatible with dbt_project.yml files that use `config-version: 2`

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

Since it doesn't hurt to use the + prefix, we recommend you use it whenever adding configs to your dbt_project.yml file.