[Core] Describe what contributes to `state:modified` for each resource type

Link to the page(s) on docs.getdbt.com requiring updates

https://docs.getdbt.com/reference/node-selection/state-comparison-caveats

Tell us more about this update

Folks will often want to understand why a change is or isn't included in state:modified.

It would be great if we documented which things contribute (and possible some examples of which don't).

Reviewers/Stakeholders/SMEs

Related GitHub issues

https://github.com/dbt-labs/dbt-bigquery/issues/1192

Additional information

state:modified is determined by check_modified_content which uses the definition of same_contents (which often varies by node type).

For example, a parsed node is considered modified if (and only if), one of the following has changed:

body
config
persisted description
fqn
database representation
contract

Models extend parsed nodes to also include:

ref representation

But generic data tests use the the following criteria instead:

config
fqn

Unit tests use:

checksum

Macros:

macro sql

Documentation ("docs blocks"):

block contents

Sources:

database_representation
fqn
config
quoting
freshness
external

Exposures:

fqn
exposure_type
owner
maturity
url
description
label
depends_on
config

Metric:

filter
metadata
type
type params
description
label
config

Semantic model:

model
description
defaults
entities
dimensions
measures
config
primary entity
group

Saved query:

metrics
group by
description
where
label
config
group
exports

Any other properties not listed above are not taken into account as it relates to state:modified. For example, if a model using the dbt-bigquery adapter defines policy_tags on one of its columns and then changes it subsequently, it will not affect the calculation of state:modified.

dbt-labs / docs.getdbt.com