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puyopuyotetr.is/db/migrate/20210505174616_update_follow_recommendations_to_version_2.rb
Claire d9ae3db8d5
Improve performance of follow recommendation scheduler (#16159)
Express follow_recommendations in terms of account_summaries rather than
accounts, integrate filters that are unconditionally used, and materialize
the resulting view.

This should result in the bulk of the computation being performed only once
instead of **once per recommendation language**.
2021-05-05 22:04:52 +02:00

19 lines
615 B
Ruby

class UpdateFollowRecommendationsToVersion2 < ActiveRecord::Migration[6.1]
# We're switching from a normal to a materialized view so we need
# custom `up` and `down` paths.
def up
drop_view :follow_recommendations
create_view :follow_recommendations, version: 2, materialized: true
# To be able to refresh the view concurrently,
# at least one unique index is required
safety_assured { add_index :follow_recommendations, :account_id, unique: true }
end
def down
drop_view :follow_recommendations, materialized: true
create_view :follow_recommendations, version: 1
end
end