add a combined index('username', 'entity_type') on module_engagement table

[muhammad-ammar]

Description: Add a combined index on module_engagement table. Index will created manually, we have opened a DE Support ticket for that.

JIRA: ENT-2548

Analytics Pipeline Pull Request

Make sure that the following steps are done before merging:

• [ ] If you have a migration please contact data engineering team before merging.
• [ ] Before merging run full acceptance tests suite and provide URL for the acceptance tests run.
• [ ] A member of data engineering team has approved the pull request.

[codecov[bot]]

Codecov Report

Merging #808 into master will not change coverage by %. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #808   +/-   ##
=======================================
  Coverage   74.37%   74.37%           
=======================================
  Files         211      211           
  Lines       24399    24399           
=======================================
  Hits        18146    18146           
  Misses       6253     6253           

Impacted Files	Coverage Δ
edx/analytics/tasks/insights/module_engagement.py	79.13% <ø> (ø)

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[brianhw]

I'm going to suggest that Hassan approve this after he applies the index to the table in production. Keep them in sync....

[muhammad-ammar]

@brianhw @HassanJaveed84 I have just verified on read replica and composite index is now added.

mysql> show indexes from module_engagement;
+-------------------+------------+----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| Table             | Non_unique | Key_name             | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+-------------------+------------+----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| module_engagement |          0 | PRIMARY              |            1 | id          | A         |   975580605 |     NULL | NULL   |      | BTREE      |         |               |
| module_engagement |          1 | course_id            |            1 | course_id   | A         |    12349121 |     NULL | NULL   |      | BTREE      |         |               |
| module_engagement |          1 | course_id            |            2 | username    | A         |    57387094 |     NULL | NULL   |      | BTREE      |         |               |
| module_engagement |          1 | course_id            |            3 | date        | A         |   325193535 |     NULL | NULL   |      | BTREE      |         |               |
| module_engagement |          1 | date                 |            1 | date        | A         |      421235 |     NULL | NULL   |      | BTREE      |         |               |
| module_engagement |          1 | username_entity_type |            1 | username    | A         |    30486893 |     NULL | NULL   |      | BTREE      |         |               |
| module_engagement |          1 | username_entity_type |            2 | entity_type | A         |    57387094 |     NULL | NULL   |      | BTREE      |         |               |
+-------------------+------------+----------------------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
7 rows in set (0.00 sec)

I think we are good to merge this PR.