Add table for storing issue tsvector

This will be used for full-text search. We store the tsvector in a
column instead of computing it from the issue columns because we need to
transform the data in Ruby before generating the tsvector.

Changelog: other

db/migrate/20211007090229_create_issue_search_table.rb

+# frozen_string_literal: true
+
+class CreateIssueSearchTable < Gitlab::Database::Migration[1.0]
+  def change
+    create_table :issue_search_data, id: false do |t|
+      t.references :issue, index: false, default: nil, primary_key: true, foreign_key: { on_delete: :cascade }, type: :bigint
+      t.timestamps_with_timezone default: -> { 'CURRENT_TIMESTAMP' }
+      t.tsvector :search_vector
+
+      t.index :search_vector, using: :gin, name: 'index_issue_search_data_on_search_vector'
+    end
+  end
+end

db/schema_migrations/20211007090229

+9d87052305a552ce380e81a33c690496c44e332eb86869ea6882f5cd4856ab93
\ No newline at end of file

db/structure.sql

@@ -15655,6 +15655,13 @@ CREATE SEQUENCE issue_metrics_id_seq
 
 ALTER SEQUENCE issue_metrics_id_seq OWNED BY issue_metrics.id;
 
+CREATE TABLE issue_search_data (
+    issue_id bigint NOT NULL,
+    created_at timestamp with time zone DEFAULT CURRENT_TIMESTAMP NOT NULL,
+    updated_at timestamp with time zone DEFAULT CURRENT_TIMESTAMP NOT NULL,
+    search_vector tsvector
+);
+
 CREATE TABLE issue_tracker_data (
     id bigint NOT NULL,
     service_id integer NOT NULL,
@@ -23711,6 +23718,9 @@ ALTER TABLE ONLY issue_links
 ALTER TABLE ONLY issue_metrics
     ADD CONSTRAINT issue_metrics_pkey PRIMARY KEY (id);
 
+ALTER TABLE ONLY issue_search_data
+    ADD CONSTRAINT issue_search_data_pkey PRIMARY KEY (issue_id);
+
 ALTER TABLE ONLY issue_tracker_data
     ADD CONSTRAINT issue_tracker_data_pkey PRIMARY KEY (id);
 
@@ -26693,6 +26703,8 @@ CREATE INDEX index_issue_metrics_on_issue_id_and_timestamps ON issue_metrics USI
 
 CREATE INDEX index_issue_on_project_id_state_id_and_blocking_issues_count ON issues USING btree (project_id, state_id, blocking_issues_count);
 
+CREATE INDEX index_issue_search_data_on_search_vector ON issue_search_data USING gin (search_vector);
+
 CREATE INDEX index_issue_tracker_data_on_service_id ON issue_tracker_data USING btree (service_id);
 
 CREATE UNIQUE INDEX index_issue_user_mentions_on_note_id ON issue_user_mentions USING btree (note_id) WHERE (note_id IS NOT NULL);
@@ -31431,6 +31443,9 @@ ALTER TABLE ONLY operations_strategies_user_lists
 ALTER TABLE ONLY issue_tracker_data
     ADD CONSTRAINT fk_rails_ccc0840427 FOREIGN KEY (service_id) REFERENCES integrations(id) ON DELETE CASCADE;
 
+ALTER TABLE ONLY issue_search_data
+    ADD CONSTRAINT fk_rails_ce5f26b01c FOREIGN KEY (issue_id) REFERENCES issues(id) ON DELETE CASCADE;
+
 ALTER TABLE ONLY resource_milestone_events
     ADD CONSTRAINT fk_rails_cedf8cce4d FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE SET NULL;
 

lib/gitlab/database/gitlab_schemas.yml

@@ -272,6 +272,7 @@ issue_emails: :gitlab_main
 issue_email_participants: :gitlab_main
 issue_links: :gitlab_main
 issue_metrics: :gitlab_main
+issue_search_data: :gitlab_main
 issues: :gitlab_main
 issues_prometheus_alert_events: :gitlab_main
 issues_self_managed_prometheus_alert_events: :gitlab_main

spec/lib/gitlab/import_export/all_models.yml

@@ -34,6 +34,7 @@ issues:
 - issuable_severity
 - issuable_sla
 - issue_assignees
+- search_data
 - closed_by
 - epic_issue
 - epic
@@ -627,6 +628,8 @@ issuable_severity:
 issue_assignees:
 - issue
 - assignee
+search_data:
+- issue
 merge_request_assignees:
 - merge_request
 - assignee