[WIP] add index on STI type columns

[durandom]

this adds indexes to all tables that have a type column which is used for STI

because I'm too lazy to do this by hand I created a small script: https://gist.github.com/durandom/b23d7e12722b2ea4f6aee20178ee9cb2

• checks if there is an index on type already (only miq_cim_instances and miq_workers)
• greps the codebase for classes inheriting from the base class
• greps the base class if NewWithTypeSti mixin got mixed in
• otherwise gives a note

Unfortunately neither the rails api docs nor guides suggest adding an index for that column. And I havent found any recent stuff on the internet. But that does not mean that it does not make sense 😄

@miq-bot add_label performance, sql migration

@kbrock because of performance
@carbonin
@Fryguy because you suggested it :)

[kbrock]

just kicking this build. if it fails again, then please rebase. thnx

[durandom]

hmm, I dont get, why this fails on travis. Locally its green

[durandom]

with echo 1 > REGION it also fails locally. But I still don't get it :/

[miq-bot]

Checked commit durandom@c4846a5 with ruby 2.2.4, rubocop 0.37.2, and haml-lint 0.16.1
1 file checked, 6 offenses detected

db/migrate/20160628142706_add_index_on_all_type_columns.rb

• ❗ - Line 16, Col 1 - Style/CommentIndentation - Incorrect indentation detected (column 0 instead of 4).
• ❗ - Line 40, Col 1 - Style/CommentIndentation - Incorrect indentation detected (column 0 instead of 4).
• ❗ - Line 53, Col 1 - Style/CommentIndentation - Incorrect indentation detected (column 0 instead of 4).
• ❗ - Line 59, Col 1 - Style/CommentIndentation - Incorrect indentation detected (column 0 instead of 4).
• ❕ - Line 2, Col 3 - Metrics/AbcSize - Assignment Branch Condition size for change is too high. [49/15]
• ❕ - Line 2, Col 3 - Metrics/MethodLength - Method has too many lines. [49/25]

[durandom]

making this WIP until I figure out whats causing CI failure

@miq-bot add_label wip

[kbrock]

Are the indexes unique or something dumb like that?

[durandom]

Are the indexes unique or something dumb like that?

nope, btree indexes

[Fryguy]

Database migrations have now been moved to the https://github.com/ManageIQ/manageiq-schema repo. Please see http://talk.manageiq.org/t/new-split-repo-manageiq-schema/2478 for instructions on how to transfer your database migrations. If this PR contains only migrations, I will leave it open for a short time during the transition, after which I will close this if it has not been moved over.

[kbrock]

wondering if some of these indexes should include type or some other columns?

[juliancheal]

@Fryguy is this something we still want to work on?

[Fryguy]

@juliancheal yes, I think this is still a good idea, but it needs to be moved to manageiq-schema.

[juliancheal]

@Fryguy ok cool

[juliancheal]

This should be closed in favour of ManageIQ/manageiq-schema#190