Redshift features not supported yet

[tunetheweb]

Copied from: #612 (comment)

Reporting a few more examples of Redshift-specific functionality:

The COPY command available in Redshift does not exist in PostgreSQL, which makes it impossible to sqlfluff lint or sqlfluff fix any COPY query, e.g.:
In test.sql:

COPY catdemo
FROM 's3://awssampledbuswest2/tickit/category_pipe.txt'
IAM_ROLE 'arn:aws:iam::<aws-account-id>:role/<role-name>'
REGION 'us-west-2';

❯ sqlfluff lint test.sql
== [test.sql] FAIL
L: 1 | P: 1 | PRS | Found unparsable section: "COPY catdemo\nFROM
| 's3://awssampledbuswes..."

A similar scenario occurs with the CREATE EXTERNAL TABLE Redshift command.

Redshift INSERT, DELETE, and UPDATE statements do not support WITH clauses as PostgreSQL does. This opens the door to having a Redshift-specific rule to catch this.

[WittierDinosaur]

I think this diverges enough to be worth having a redshift dialect

[tunetheweb]

Yup that's what I thought: See: #1641

At the moment based on postgres which I think makes sense. But know you had some concerns before on that (but I think on dialects that didn't really have much in common with postgres to be honest) so let me know your thoughts.

[farfromunique]

Redshift dialect support was added in 0.7.0, it seems. Should this issue be closed?

[tunetheweb]

There were a few items listed in #612 before Redshift was supported. The ones above were not in that initial support (when I closed #612 as we no do support Redshift as you say). So copied to this new issue. Not sure if those specific examples are supported now, and they probably should be individual, more detailed descriptions to be honest.

Let's close and get people to open new issues with more detail if they need those functionalist and they don't yet exist.