~~~The database was created using the PostgreSQL database management system suitable for large datasets and complex SQL-queries. The database was modified with PgSphere plugin required for work with sky coordinates. Data entry to the database was done using online Vizier archive from the Strasbourg astronomical Data Center and Optical Character Recognition (OCR) system FineReader in the cases when online data is not available. DBSCAN algorithm of Python SCIKIT-LEARN package is used for source grouping. Matching with the external datasets is done with x-match service of the Strasbourg astronomical Data Center. The online web-interface is written using Perl/CGI language with the support of the Javascript (including AJAX technology). Online plots in the web-interface are plotted using Plotly JS graphics library.
~~~Moto "the simplest solution is almost always the best" guided us in the sense of data storage, thus it is essential to not overload the database with deep decompositions to simplify the SQL-queries. For example, for the class I and class II methanol masers, the actual observational data (including non-detections) is stored in the tables met1_data and met2_data. The interferometric maser spot data for both class I and class II masers is stored in the table maser_spots to prevent overload of the main observation table. The interferometric spot table is connected to the observation tables with a simple integer identifier obs_id. Result of observations grouping (done with DBSCAN algorithm) is stored in the view all_objects and is recalculated with each database update. The grouping table is connected to the main observation table with grp column, identifying a source group in format of galactic coordinates "G55.371+0.185". External data (including fluxes) is stored locally in the following tables: iras, akari, bgps, atlasgal, ego and a few others. The table transitions stores the known methanol maser transitions, table papers stores the paper information (abstract, reference, data type, etc.), and table stat stores the statistics (number of detections, etc.).
Read our paper for more information:
Online Database of Class I Methanol Masers
D. A. Ladeyschikov, O. S. Bayandina, and A. M. Sobolev
2019, The Astronomical Journal, 158, 233

The main search page of the database web-interface.