Hydrologic data management using RDBMS with Differential-Linear Data Storage

Recently, Relational Data Base Management Systems (RDBMSs) have become popular for handling hydrologic time-series and running hydrologic applications. However, the standard data independence in such systems has many technical disadvantages in storing time-series data. An alternative technique, named Differential-Linear Data Storage (DLDS) technique, has been developed in the framework of the Hydroscope project (a Greek nation-wide database for hydrometeorological information). This technique establishes a standardised representation of hydrologic time-series in a relational database environment, also providing a notable reduction in storage space. Instead of the standard SQL queries (select, insert, delete and update), numerous composite procedures are implemented to facilitate time-series management.