Enable create or replace sql syntax

[Fokko]

With Delta we can do an atomic operation to replace the current version of the table, with a new version using the create or replace syntax.

For delta, and only delta, we can use the CREATE OR REPLACE syntax to atomically replace the table. This will make sure that the table is still available all the time.

resolves #124

Description

Checklist

• 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 updated the CHANGELOG.md and added information about my change to the "dbt next" section.

Ran the tests:

MacBook-Pro-van-Fokko:dbt-integration-tests fokkodriesprong$ ./bin/run-with-profile default
Test direct copying of source tables    # features/001_basic_materializations.feature
  Test materialized='view' -- @1.1   ..........
  Test materialized='table' -- @1.2   ..........
  Test materialized='incremental' -- @1.3   ..........

Test re-materializing models as different types    # features/002_rematerialize_models.feature
  Materialize as view (view) first, then view (view) -- @1.1   ............
  Materialize as view (view) first, then table (parquet) -- @1.2   ............
  Materialize as view (view) first, then incremental (parquet) -- @1.3   ............
  Materialize as table (parquet) first, then view (view) -- @1.4   ............
  Materialize as table (delta) first, then view (view) -- @1.5   ............
  Materialize as table (parquet) first, then table (parquet) -- @1.6   ............
  Materialize as table (parquet) first, then table (delta) -- @1.7   ............
  Materialize as table (delta) first, then table (parquet) -- @1.8   ............
  Materialize as table (delta) first, then table (delta) -- @1.9   ............
  Materialize as table (parquet) first, then incremental (parquet) -- @1.10   ............
  Materialize as table (parquet) first, then incremental (parquet) -- @1.11   ............
  Materialize as incremental (parquet) first, then view (view) -- @1.12   ............
  Materialize as incremental (parquet) first, then table (parquet) -- @1.13   ............
  Materialize as incremental (parquet) first, then incremental (parquet) -- @1.14   ............

2 features passed, 0 failed, 0 skipped
17 scenarios passed, 0 failed, 0 skipped
198 steps passed, 0 failed, 0 skipped, 0 undefined
Took 17m21.438s

[jtcohen6]

Going to figure out why Circle didn't run tests against this PR

[jtcohen6]

Hey @Fokko, I think the issue here is that the CI jobs ran against the fork in the "Fokko" Circle organization as opposed to the "Fishtown Analytics" ones (which have the appropriate env vars for sandbox Databricks connection). I believe this is fixable if you go into the CircleCI Project Settings for the "Fokko" organization, and on the Overview tab, click Stop Building, such that CircleCI should no longer follow Fokko / dbt.

[Fokko]

@jtcohen6 Sorry for the late reply, was kinda busy. I couldn't find the page that you're referring to. I've unfollowed the project in CircleCI, let's see if that fixes anything.

[jtcohen6]

@Fokko This looks great! Thanks for getting the CI working.

If you're up to do it, I'd support swapping out the existing {% if config.file_format == 'delta' %} checks in incremental + snapshot to use relation.is_delta instead. That doesn't need to happen in this PR, though.

[Fokko]

@jtcohen6 I've reverted the incremental.sql as well. The .is_delta only works for existing relations :)

[jtcohen6]

Fair enough, it was a nice thought :) I'm quite happy with this!

@Fokko could you add a changelog entry (and add yourself to the list of contributors)? I'd love to get this in before v0.19.0.

The failing test seems to be an unrelated issue with set statements + the new SQL Analytics endpoints. I'll open a separate PR to disable the incremental step for that test suite.

[Fokko]

@jtcohen6 thanks! I've added myself to the CHANGELOG. And!