Support query_group for WLM

[Surgo]

Subject: Set query_group for WLM

Feature or Bugfix

• Feature
• Bugfix

Purpose

• Set query_group when create connection

Detail

• Run SET query_group TO <specific query group by OPTIONS>

Relates

• https://docs.aws.amazon.com/redshift/latest/dg/cm-c-implementing-workload-management.html
• https://docs.aws.amazon.com/redshift/latest/dg/r_query_group.html

[shimizukawa]

(It's my first Draft pull request! If this become a non-draft PR, I should review it.)

[Surgo]

I'll testing on my application :)

[Surgo]

Check on my application

• My settings 'OPTIONS': {'query_group': 'report'}

• Check queries are labeled to 'report' in svl_qlog

  select query, pid, substring, elapsed, label from svl_qlog where label ='report' order by query;
    query  |  pid  |                          substring                           | elapsed |             label
  ---------+-------+--------------------------------------------------------------+---------+--------------------------------
   7964883 | 11061 | ************************************************************ | 2189779 | report
   7964910 | 11826 | ************************************************************ |   63912 | report
   7964916 | 11848 | ************************************************************ |   29222 | report
   7964917 | 11847 | ************************************************************ |  128189 | report
   7964926 | 11901 | ************************************************************ |   50180 | report
   7964927 | 11902 | ************************************************************ |   95262 | report
   7964930 | 11907 | ************************************************************ |   56460 | report
   7964931 | 11908 | ************************************************************ | 2937231 | report
   7964932 | 11927 | ************************************************************ | 7731372 | report
   7964933 | 11929 | ************************************************************ | 7613961 | report
  (10 rows)

  Raw SQLs (substring) are masked :)

Its works fine for me.

[Surgo]

My application using new query group :)

@shimizukawa This PR is ready fore review. Please review it.

[shimizukawa]

Commented.

[shimizukawa]

1.0.1 means PATCH version that should be used for minor bug fix.
1.1.0 is good for 'New Features' on semver.

[shimizukawa]

I think it would be better that self.query_group is initialized with None on __Init__ method or class variable. (I know init_connection_state always called after get_connection_params)

[shimizukawa]

Why are you using LIST type for assignments variable?
It seems it only have single string object in this method.

[Surgo]

@shimizukawa Thank you for your review. I'll fix it :)

[shimizukawa]

@Surgo how about this?

[Surgo]

@shimizukawa I'm sorry but to busy now... I'll fix within weeks..

[shimizukawa]

OK, no problem. It's just a reminder :)