Binary star DataBase (BDB) is the database of binary/multiple systems of various observational types. BDB contains data on physical and positional parameters of 260,000 components of 120,000 stellar systems of multiplicity 2 to more than 20, taken from a large variety of published catalogues and databases. We describe the new features in organization of the database, integration of new catalogues and implementation of new possibilities available to users. The development of the BDB index-catalogue, Identification List of Binaries, is discussed. This star catalogue provides cross-referencing between most popular catalogues of binary stars. We describe ideas and methods for reliable cross-identification of different entities (systems, pairs, components) in binary and multiple stellar systems.

We present the result of comparison of Gaia DR2 parallaxes and photometry with data derived from a combined analysis of 2MASS, SDSS, GALEX, and UKIDSS surveys in four selected high-latitude sky areas. We have shown that, under certain circumstances, multicolor photometric data from large modern surveys can be successfully used for parameterization of stars, including estimation of distance and interstellar extinction value.