Feature/support incremental predicates

[dave-connors-3]

resolves #5680

Description

This PR incorporates the feedback from @NiallRees in #5679 and builds on it for the delete+insert incremental strategy. There's not a ton of functional difference between the two PRs:

• small difference in handling parentheses
• I made some argument changes to be a bit more consistent with naming and how incremental_predicates gets passed through the arg_dict
• added changes for get_delete_insert_merge_sql for predicates in the style described by Niall

In conjunction with this PR, i added support across the other adapters that use merge or delete+insert:

• BQ
• Spark
• Databricks

UPDATE - opened new PR for Snowflake adapter tests

• Snowflake

Would love some guidance on how to coordinate these changes together (esp Databricks, since it's a forked repo!)

I made a new PR simply becuase I had the branch in motion -- I recognize this is probably to most annoying way to do this given how many versions of this PR there have been, and the fact that it's duplicative to Niall's -- many apologies! Happy to coordinate and consolidate however the team sees fit.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have signed the CLA
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have opened an issue to add/update docs, or docs changes are not required/relevant for this PR
  • Adding 'incremental_predicates1 information docs.getdbt.com#2681
• I have run changie new to create a changelog entry

[github-actions]

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[NiallRees]

Pls pls pls can we get this into the next minor release? For some reason I thought it would be released in 1.3.0 until I just checked!

[NiallRees]

For those who want this now, all you have to do to get the incremental_predicates config working is add this macro override:

{% macro default__get_incremental_merge_sql(arg_dict) %}

  {% do return(get_merge_sql(arg_dict["target_relation"], arg_dict["temp_relation"], arg_dict["unique_key"], arg_dict["dest_columns"], arg_dict["predicates"])) %}

{% endmacro %}

[colin-rogers-dbt]

One thought is that we could maybe support both, borrowing from @NiallRees :

{% macro default__get_incremental_merge_sql(arg_dict) %}
  {% if "predicates" in arg_dict %}
    {% do return(get_merge_sql(arg_dict["target_relation"], arg_dict["temp_relation"], arg_dict["unique_key"], arg_dict["dest_columns"], arg_dict["predicates"])) %}
  {% else %}
    {% do return(get_delete_insert_merge_sql(arg_dict["target_relation"], arg_dict["temp_relation"], arg_dict["unique_key"], arg_dict["dest_columns"], arg_dict["incremental_predicates"])) %}
{% endmacro %}

[colin-rogers-dbt]

LGTM