Re: Re: PostgreSQL versus MySQL

Doug, You've posted your usual good sense, combined with one statement I strongly disagree with.

One of these products is a relational database management system. The other is a quasi-SQL-like-front-end-to-systems-of-indexed-files that has never concerned itself with things like standards conformance.

The implication is that MySQL is not an RDBMS. The only attempt I know of to define an RDBMS was Codd's, and no DBMS has ever met the criteria he published in a paper in the late 80s (1986?). Even though Oracle doesn't meet the criteria of the best known definition (only definition?) of an RDBMS, we all seem to agree that Oracle is an RDBMS. An RDBMS is a DBMS designed to manage a relational database, and a database is relational because it stores data in linked, normalized tables. In general, the term RDBMS is used to mean a DBMS that can be used to create, modify, and extract data from normalized tables. This covers the functionality described in Codd's early papers and doesn't exclude all existing DBMSs. No RDBMS provides a dialect of SQL that conforms perfectly to the standard. The MySQL interface uses a dialect that conforms in the most important areas. The conformance is close enough that someone like me, who refuses to learn non-SQL interfaces because they can only be used with the DBMS they were designed for, is perfectly comfortable with the MySQL interface. Given the different versions of the SQL standard, and the variety of non-standard implementations, it seems pretty arbitrary to call one vendor's SQL dialect 'SQL' and another's 'quasi-SQL'. And whether the DBMS implements its databases as systems of indexed files, or through some other system, looks pretty irrelevant from my porch. Know thyself? Absurd direction!

Bubbles bear no introspection.     -Khushhal Khan Khatak