diff options
Diffstat (limited to 'db/migrate/20170927122209_add_partial_index_for_labels_template.rb')
-rw-r--r-- | db/migrate/20170927122209_add_partial_index_for_labels_template.rb | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/db/migrate/20170927122209_add_partial_index_for_labels_template.rb b/db/migrate/20170927122209_add_partial_index_for_labels_template.rb new file mode 100644 index 00000000000..c3e5077ba20 --- /dev/null +++ b/db/migrate/20170927122209_add_partial_index_for_labels_template.rb @@ -0,0 +1,45 @@ +# See http://doc.gitlab.com/ce/development/migration_style_guide.html +# for more information on how to write migrations for GitLab. + +class AddPartialIndexForLabelsTemplate < ActiveRecord::Migration + include Gitlab::Database::MigrationHelpers + + # Set this constant to true if this migration requires downtime. + DOWNTIME = false + + # When a migration requires downtime you **must** uncomment the following + # constant and define a short and easy to understand explanation as to why the + # migration requires downtime. + # DOWNTIME_REASON = '' + + # When using the methods "add_concurrent_index", "remove_concurrent_index" or + # "add_column_with_default" you must disable the use of transactions + # as these methods can not run in an existing transaction. + # When using "add_concurrent_index" or "remove_concurrent_index" methods make sure + # that either of them is the _only_ method called in the migration, + # any other changes should go in a separate migration. + # This ensures that upon failure _only_ the index creation or removing fails + # and can be retried or reverted easily. + # + # To disable transactions uncomment the following line and remove these + # comments: + + disable_ddl_transaction! + + # Note this is a partial index in Postgres but MySQL will ignore the + # partial index clause. By making it an index on "template" this + # means the index will still accomplish the same goal of optimizing + # a query with "where template = true" on MySQL -- it'll just take + # more space. In this case the number of records with template=true + # is expected to be very small (small enough to display on a single + # web page) so it's ok to filter or sort them without the index + # anyways. + + def up + add_concurrent_index "labels", ["template"], where: "template" + end + + def down + remove_concurrent_index "labels", ["template"], where: "template" + end +end |