Move category creation and UUID update to a more performant data migration (#3437)

* Move category creation and UUID update to a more performant data migration

* Fix linter

* Fix linter

server/services/store/sqlstore/data_migrations.go

@@ -14,6 +14,11 @@ import (
 )
 
 const (
+	// we group the inserts on batches of 1000 because PostgreSQL
+	// supports a limit of around 64K values (not rows) on an insert
+	// query, so we want to stay safely below.
+	CategoryInsertBatch = 1000
+
 	TemplatesToTeamsMigrationKey = "TemplatesToTeamsMigrationComplete"
 	UniqueIDsMigrationKey        = "UniqueIDsMigrationComplete"
 	CategoryUUIDIDMigrationKey   = "CategoryUuidIdMigrationComplete"
@@ -122,6 +127,10 @@ func (s *SQLStore) runUniqueIDsMigration() error {
 	return nil
 }
 
+// runCategoryUUIDIDMigration takes care of deriving the categories
+// from the boards and its memberships. The name references UUID
+// because of the preexisting purpose of this migration, and has been
+// preserved for compatibility with already migrated instances.
 func (s *SQLStore) runCategoryUUIDIDMigration() error {
 	setting, err := s.GetSystemSetting(CategoryUUIDIDMigrationKey)
 	if err != nil {
@@ -140,146 +149,196 @@ func (s *SQLStore) runCategoryUUIDIDMigration() error {
 		return txErr
 	}
 
-	if err := s.updateCategoryIDs(tx); err != nil {
-		return err
-	}
+	if s.isPlugin {
+		if err := s.createCategories(tx); err != nil {
+			if rollbackErr := tx.Rollback(); rollbackErr != nil {
+				s.logger.Error("category UUIDs insert categories transaction rollback error", mlog.Err(rollbackErr), mlog.String("methodName", "setSystemSetting"))
+			}
+			return err
+		}
 
-	if err := s.updateCategoryBlocksIDs(tx); err != nil {
-		return err
+		if err := s.createCategoryBoards(tx); err != nil {
+			if rollbackErr := tx.Rollback(); rollbackErr != nil {
+				s.logger.Error("category UUIDs insert category boards transaction rollback error", mlog.Err(rollbackErr), mlog.String("methodName", "setSystemSetting"))
+			}
+			return err
+		}
 	}
 
 	if err := s.setSystemSetting(tx, CategoryUUIDIDMigrationKey, strconv.FormatBool(true)); err != nil {
 		if rollbackErr := tx.Rollback(); rollbackErr != nil {
-			s.logger.Error("category IDs transaction rollback error", mlog.Err(rollbackErr), mlog.String("methodName", "setSystemSetting"))
+			s.logger.Error("category UUIDs transaction rollback error", mlog.Err(rollbackErr), mlog.String("methodName", "setSystemSetting"))
 		}
 		return fmt.Errorf("cannot mark migration as completed: %w", err)
 	}
 
 	if err := tx.Commit(); err != nil {
-		return fmt.Errorf("cannot commit category IDs transaction: %w", err)
+		return fmt.Errorf("cannot commit category UUIDs transaction: %w", err)
 	}
 
-	s.logger.Debug("category IDs migration finished successfully")
+	s.logger.Debug("category UUIDs migration finished successfully")
 	return nil
 }
 
-func (s *SQLStore) updateCategoryIDs(db sq.BaseRunner) error {
-	// fetch all category IDs
-	oldCategoryIDs, err := s.getIDs(db, "categories")
-	if err != nil {
-		return err
-	}
-
-	// map old category ID to new ID
-	categoryIDs := map[string]string{}
-	for _, oldID := range oldCategoryIDs {
-		newID := utils.NewID(utils.IDTypeNone)
-		categoryIDs[oldID] = newID
-	}
-
-	// update for each category ID.
-	// Update the new ID in category table,
-	// and update corresponding rows in category boards table.
-	for oldID, newID := range categoryIDs {
-		if err := s.updateCategoryID(db, oldID, newID); err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-func (s *SQLStore) getIDs(db sq.BaseRunner, table string) ([]string, error) {
+func (s *SQLStore) createCategories(db sq.BaseRunner) error {
 	rows, err := s.getQueryBuilder(db).
-		Select("id").
-		From(s.tablePrefix + table).
+		Select("c.DisplayName, cm.UserId, c.TeamId, cm.ChannelId").
+		From(s.tablePrefix + "boards boards").
+		Join("ChannelMembers cm on boards.channel_id = cm.ChannelId").
+		Join("Channels c on cm.ChannelId = c.id and (c.Type = 'O' or c.Type = 'P')").
+		GroupBy("cm.UserId, c.TeamId, cm.ChannelId, c.DisplayName").
 		Query()
 
 	if err != nil {
-		s.logger.Error("getIDs error", mlog.String("table", table), mlog.Err(err))
-		return nil, err
+		s.logger.Error("get boards data error", mlog.Err(err))
+		return err
 	}
 	defer s.CloseRows(rows)
 
-	var categoryIDs []string
+	initQuery := func() sq.InsertBuilder {
+		return s.getQueryBuilder(db).
+			Insert(s.tablePrefix+"categories").
+			Columns(
+				"id",
+				"name",
+				"user_id",
+				"team_id",
+				"channel_id",
+				"create_at",
+				"update_at",
+				"delete_at",
+			)
+	}
+	// query will accumulate the insert values until the limit is
+	// reached, and then it will be stored and reset
+	query := initQuery()
+	// queryList stores those queries that already reached the limit
+	// to be run when all the data is processed
+	queryList := []sq.InsertBuilder{}
+	counter := 0
+	now := model.GetMillis()
+
 	for rows.Next() {
-		var id string
-		err := rows.Scan(&id)
+		var displayName string
+		var userID string
+		var teamID string
+		var channelID string
+
+		err := rows.Scan(
+			&displayName,
+			&userID,
+			&teamID,
+			&channelID,
+		)
 		if err != nil {
-			s.logger.Error("getIDs scan row error", mlog.String("table", table), mlog.Err(err))
-			return nil, err
+			return fmt.Errorf("cannot scan result while trying to create categories: %w", err)
 		}
 
-		categoryIDs = append(categoryIDs, id)
+		query = query.Values(
+			utils.NewID(utils.IDTypeNone),
+			displayName,
+			userID,
+			teamID,
+			channelID,
+			now,
+			0,
+			0,
+		)
+
+		counter++
+		if counter%CategoryInsertBatch == 0 {
+			queryList = append(queryList, query)
+			query = initQuery()
+		}
 	}
 
-	return categoryIDs, nil
-}
-
-func (s *SQLStore) updateCategoryID(db sq.BaseRunner, oldID, newID string) error {
-	// update in category table
-	_, err := s.getQueryBuilder(db).
-		Update(s.tablePrefix+"categories").
-		Set("id", newID).
-		Where(sq.Eq{"id": oldID}).
-		Exec()
-
-	if err != nil {
-		s.logger.Error("updateCategoryID update category error", mlog.Err(err))
-		return err
+	if counter%CategoryInsertBatch != 0 {
+		queryList = append(queryList, query)
 	}
 
-	// update category boards table
-	_, err = s.getQueryBuilder(db).
-		Update(s.tablePrefix+"category_boards").
-		Set("category_id", newID).
-		Where(sq.Eq{"category_id": oldID}).
-		Exec()
-
-	if err != nil {
-		s.logger.Error("updateCategoryID update category boards error", mlog.Err(err))
-		return err
+	for _, q := range queryList {
+		if _, err := q.Exec(); err != nil {
+			return fmt.Errorf("cannot create category values: %w", err)
+		}
 	}
 
 	return nil
 }
 
-func (s *SQLStore) updateCategoryBlocksIDs(db sq.BaseRunner) error {
-	// fetch all category IDs
-	oldCategoryIDs, err := s.getIDs(db, "category_boards")
+func (s *SQLStore) createCategoryBoards(db sq.BaseRunner) error {
+	rows, err := s.getQueryBuilder(db).
+		Select("categories.user_id, categories.id, boards.id").
+		From(s.tablePrefix + "categories categories").
+		Join(s.tablePrefix + "boards boards on categories.channel_id = boards.channel_id AND boards.is_template = false").
+		Query()
+
 	if err != nil {
+		s.logger.Error("get categories data error", mlog.Err(err))
 		return err
 	}
+	defer s.CloseRows(rows)
 
-	// map old category ID to new ID
-	categoryIDs := map[string]string{}
-	for _, oldID := range oldCategoryIDs {
-		newID := utils.NewID(utils.IDTypeNone)
-		categoryIDs[oldID] = newID
+	initQuery := func() sq.InsertBuilder {
+		return s.getQueryBuilder(db).
+			Insert(s.tablePrefix+"category_boards").
+			Columns(
+				"id",
+				"user_id",
+				"category_id",
+				"board_id",
+				"create_at",
+				"update_at",
+				"delete_at",
+			)
 	}
+	// query will accumulate the insert values until the limit is
+	// reached, and then it will be stored and reset
+	query := initQuery()
+	// queryList stores those queries that already reached the limit
+	// to be run when all the data is processed
+	queryList := []sq.InsertBuilder{}
+	counter := 0
+	now := model.GetMillis()
 
-	// update for each category ID.
-	// Update the new ID in category table,
-	// and update corresponding rows in category boards table.
-	for oldID, newID := range categoryIDs {
-		if err := s.updateCategoryBlocksID(db, oldID, newID); err != nil {
-			return err
+	for rows.Next() {
+		var userID string
+		var categoryID string
+		var boardID string
+
+		err := rows.Scan(
+			&userID,
+			&categoryID,
+			&boardID,
+		)
+		if err != nil {
+			return fmt.Errorf("cannot scan result while trying to create category boards: %w", err)
+		}
+
+		query = query.Values(
+			utils.NewID(utils.IDTypeNone),
+			userID,
+			categoryID,
+			boardID,
+			now,
+			0,
+			0,
+		)
+
+		counter++
+		if counter%CategoryInsertBatch == 0 {
+			queryList = append(queryList, query)
+			query = initQuery()
 		}
 	}
-	return nil
-}
 
-func (s *SQLStore) updateCategoryBlocksID(db sq.BaseRunner, oldID, newID string) error {
-	// update in category table
-	_, err := s.getQueryBuilder(db).
-		Update(s.tablePrefix+"category_boards").
-		Set("id", newID).
-		Where(sq.Eq{"id": oldID}).
-		Exec()
+	if counter%CategoryInsertBatch != 0 {
+		queryList = append(queryList, query)
+	}
 
-	if err != nil {
-		s.logger.Error("updateCategoryBlocksID update category error", mlog.Err(err))
-		return err
+	for _, q := range queryList {
+		if _, err := q.Exec(); err != nil {
+			return fmt.Errorf("cannot create category boards values: %w", err)
+		}
 	}
 
 	return nil

server/services/store/sqlstore/migrations/000019_populate_categories.up.sql

@@ -11,36 +11,3 @@ CREATE TABLE IF NOT EXISTS {{.prefix}}categories (
     ) {{if .mysql}}DEFAULT CHARACTER SET utf8mb4{{end}};
 
 CREATE INDEX idx_categories_user_id_team_id ON {{.prefix}}categories(user_id, team_id);
-
-{{if .plugin}}
-    INSERT INTO {{.prefix}}categories(
-        id,
-        name,
-        user_id,
-        team_id,
-        channel_id,
-        create_at,
-        update_at,
-        delete_at
-    )
-    SELECT
-        {{ if .postgres }}
-            REPLACE(uuid_in(md5(random()::text || clock_timestamp()::text)::cstring)::varchar, '-', ''),
-        {{ end }}
-        {{ if .mysql }}
-            UUID(),
-        {{ end }}
-        c.DisplayName,
-        cm.UserId,
-        c.TeamId,
-        cm.ChannelId,
-        {{if .postgres}}(extract(epoch from now())*1000)::bigint,{{end}}
-        {{if .mysql}}UNIX_TIMESTAMP() * 1000,{{end}}
-        0,
-        0
-    FROM
-        {{.prefix}}boards boards
-            JOIN ChannelMembers cm on boards.channel_id = cm.ChannelId
-            JOIN Channels c on cm.ChannelId = c.id and (c.Type = 'O' or c.Type = 'P')
-    GROUP BY cm.UserId, c.TeamId, cm.ChannelId, c.DisplayName;
-{{end}}

server/services/store/sqlstore/migrations/000020_populate_category_blocks.up.sql

@@ -7,28 +7,6 @@ CREATE TABLE IF NOT EXISTS {{.prefix}}category_boards (
     update_at BIGINT,
     delete_at BIGINT,
     PRIMARY KEY (id)
-    ) {{if .mysql}}DEFAULT CHARACTER SET utf8mb4{{end}};
+) {{if .mysql}}DEFAULT CHARACTER SET utf8mb4{{end}};
 
 CREATE INDEX idx_categoryboards_category_id ON {{.prefix}}category_boards(category_id);
-
-{{if .plugin}}
-    INSERT INTO {{.prefix}}category_boards(id, user_id, category_id, board_id, create_at, update_at, delete_at)
-    SELECT
-        {{ if .postgres }}
-            REPLACE(uuid_in(md5(random()::text || clock_timestamp()::text)::cstring)::varchar, '-', ''),
-        {{ end }}
-        {{ if .mysql }}
-            UUID(),
-        {{ end }}
-        {{.prefix}}categories.user_id,
-        {{.prefix}}categories.id,
-        {{.prefix}}boards.id,
-        {{if .postgres}}(extract(epoch from now())*1000)::bigint,{{end}}
-        {{if .mysql}}UNIX_TIMESTAMP() * 1000,{{end}}
-        0,
-        0
-    FROM
-        {{.prefix}}categories
-        JOIN {{.prefix}}boards ON {{.prefix}}categories.channel_id = {{.prefix}}boards.channel_id
-        AND {{.prefix}}boards.is_template = false;
-{{end}}