Our SQL-backend family is contantly growing. Rax could already connect to SQLite, MySQL and PostgreSQL databases. Now we have also ported Rax to two major cloud databases: Microsoft Azure and AWS Redshift. The port to Azure gave us some headache due to problems with their ODBC driver for Linux. The port to Redshift was straightforward, …
Those of you who paid attention at your ‘Introduction to Databases’ class will probably remember that SQL is based on Relational Algebra. Maybe you also remember that Relational Algebra operates on relations, which are a special category of sets. As such, they do not contain duplicates. An SQL table, however, can easily contain duplicate rows and therefore it’s …
with x( s, ind ) as ( select sud, instr( sud, ‘ ‘ ) from ( select ’53 7 6 195 98 6 8 6 34 8 3 17 2 6 6 28 419 5 8 79’ sud from dual ) union all select substr( s, 1, ind – 1 ) || z || substr( …