113 lines
4.6 KiB
Ruby
113 lines
4.6 KiB
Ruby
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# 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 RemoveRedundantIndexes < ActiveRecord::Migration
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include Gitlab::Database::MigrationHelpers
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DOWNTIME = false
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disable_ddl_transaction!
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def up
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indexes = [
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[:ci_taggings, 'ci_taggings_idx'],
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[:audit_events, 'index_audit_events_on_author_id'],
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[:audit_events, 'index_audit_events_on_type'],
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[:ci_builds, 'index_ci_builds_on_erased_by_id'],
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[:ci_builds, 'index_ci_builds_on_project_id_and_commit_id'],
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[:ci_builds, 'index_ci_builds_on_type'],
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[:ci_commits, 'index_ci_commits_on_project_id'],
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[:ci_commits, 'index_ci_commits_on_project_id_and_committed_at'],
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[:ci_commits, 'index_ci_commits_on_project_id_and_committed_at_and_id'],
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[:ci_commits, 'index_ci_commits_on_project_id_and_sha'],
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[:ci_commits, 'index_ci_commits_on_sha'],
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[:ci_events, 'index_ci_events_on_created_at'],
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[:ci_events, 'index_ci_events_on_is_admin'],
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[:ci_events, 'index_ci_events_on_project_id'],
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[:ci_jobs, 'index_ci_jobs_on_deleted_at'],
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[:ci_jobs, 'index_ci_jobs_on_project_id'],
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[:ci_projects, 'index_ci_projects_on_gitlab_id'],
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[:ci_projects, 'index_ci_projects_on_shared_runners_enabled'],
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[:ci_services, 'index_ci_services_on_project_id'],
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[:ci_sessions, 'index_ci_sessions_on_session_id'],
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[:ci_sessions, 'index_ci_sessions_on_updated_at'],
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[:ci_tags, 'index_ci_tags_on_name'],
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[:ci_triggers, 'index_ci_triggers_on_deleted_at'],
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[:identities, 'index_identities_on_created_at_and_id'],
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[:issues, 'index_issues_on_title'],
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[:keys, 'index_keys_on_created_at_and_id'],
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[:members, 'index_members_on_created_at_and_id'],
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[:members, 'index_members_on_type'],
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[:milestones, 'index_milestones_on_created_at_and_id'],
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[:namespaces, 'index_namespaces_on_visibility_level'],
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[:projects, 'index_projects_on_builds_enabled_and_shared_runners_enabled'],
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[:services, 'index_services_on_category'],
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[:services, 'index_services_on_created_at_and_id'],
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[:services, 'index_services_on_default'],
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[:snippets, 'index_snippets_on_created_at'],
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[:snippets, 'index_snippets_on_created_at_and_id'],
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[:todos, 'index_todos_on_state'],
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[:web_hooks, 'index_web_hooks_on_created_at_and_id'],
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# These indexes _may_ be used but they can be replaced by other existing
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# indexes.
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# There's already a composite index on (project_id, iid) which means that
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# a separate index for _just_ project_id is not needed.
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[:issues, 'index_issues_on_project_id'],
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# These are all composite indexes for the columns (created_at, id). In all
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# these cases there's already a standalone index for "created_at" which
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# can be used instead.
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#
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# Because the "id" column of these composite indexes is never needed (due
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# to "id" already being indexed as its a primary key) these composite
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# indexes are useless.
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[:issues, 'index_issues_on_created_at_and_id'],
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[:merge_requests, 'index_merge_requests_on_created_at_and_id'],
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[:namespaces, 'index_namespaces_on_created_at_and_id'],
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[:notes, 'index_notes_on_created_at_and_id'],
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[:projects, 'index_projects_on_created_at_and_id'],
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[:users, 'index_users_on_created_at_and_id'],
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]
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transaction do
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indexes.each do |(table, index)|
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remove_index(table, name: index) if index_exists_by_name?(table, index)
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end
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end
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add_concurrent_index(:users, :created_at)
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add_concurrent_index(:projects, :created_at)
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add_concurrent_index(:namespaces, :created_at)
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end
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def down
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# We're only restoring the composite indexes that could be replaced with
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# individual ones, just in case somebody would ever want to revert.
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transaction do
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remove_index(:users, :created_at)
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remove_index(:projects, :created_at)
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remove_index(:namespaces, :created_at)
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end
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[:issues, :merge_requests, :namespaces, :notes, :projects, :users].each do |table|
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add_concurrent_index(table, [:created_at, :id],
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name: "index_#{table}_on_created_at_and_id")
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end
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end
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# Rails' index_exists? doesn't work when you only give it a table and index
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# name. As such we have to use some extra code to check if an index exists for
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# a given name.
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def index_exists_by_name?(table, index)
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indexes_for_table[table].include?(index)
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end
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def indexes_for_table
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@indexes_for_table ||= Hash.new do |hash, table_name|
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hash[table_name] = indexes(table_name).map(&:name)
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end
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end
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end
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