BaikalDB is a distributed enhanced structured database system. It supports sequential and randomised realtime read/write of structural data in petabytes-scale. BaikalDB is compatible with MySQL protocol and it supports MySQL style SQL dialect, by which users can migrate their data storage from MySQL to BaikalDB seamlessly. BaikalDB internally provides projections, filter operators (corresponding with SQL WHERE or HAVING clause), aggregation operators (corresponding with GROPY BY clause) and sort operators (corresponding with SQL ORDER BY), with which users can fulfill their complex and time-critical anayltical and transational requirement by writing SQL statements. In a typical scenario, hundreds of millions of rows can be scanned and aggregated in few seconds. BaikalDB also supports full-text search by building inverted indices after words segmentation. Users can harness fuzzy search feature simply by adding a FULLTEXT KEY type index when creating tables and then use LIKE clause in their queries.