46 lines
1.8 KiB
Ruby
46 lines
1.8 KiB
Ruby
# See http://doc.gitlab.com/ce/development/migration_style_guide.html
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# for more information on how to write migrations for GitLab.
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class AddPartialIndexForLabelsTemplate < ActiveRecord::Migration[4.2]
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include Gitlab::Database::MigrationHelpers
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# Set this constant to true if this migration requires downtime.
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DOWNTIME = false
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# When a migration requires downtime you **must** uncomment the following
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# constant and define a short and easy to understand explanation as to why the
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# migration requires downtime.
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# DOWNTIME_REASON = ''
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# When using the methods "add_concurrent_index", "remove_concurrent_index" or
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# "add_column_with_default" you must disable the use of transactions
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# as these methods can not run in an existing transaction.
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# When using "add_concurrent_index" or "remove_concurrent_index" methods make sure
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# that either of them is the _only_ method called in the migration,
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# any other changes should go in a separate migration.
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# This ensures that upon failure _only_ the index creation or removing fails
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# and can be retried or reverted easily.
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#
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# To disable transactions uncomment the following line and remove these
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# comments:
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disable_ddl_transaction!
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# Note this is a partial index in Postgres but MySQL will ignore the
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# partial index clause. By making it an index on "template" this
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# means the index will still accomplish the same goal of optimizing
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# a query with "where template = true" on MySQL -- it'll just take
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# more space. In this case the number of records with template=true
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# is expected to be very small (small enough to display on a single
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# web page) so it's ok to filter or sort them without the index
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# anyways.
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def up
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add_concurrent_index "labels", ["template"], where: "template"
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end
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def down
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remove_concurrent_index "labels", ["template"], where: "template"
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end
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end
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