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Query: keep your productivity if you migrate

In the field of open source, there are only a few major relational databases - MySQL, Postgres and Firebird. MySQL has been garnering prominent wins recently, whereas Firebird has been steadily chugging along with relatively little publicity. But the book shows that if you are considering a free database, you should seriously look at Firebird. The book describes a very highly fleshed out database, that supports much standard SQL querying. Plus Firebird has had stored procedures and foreign keys for some time. The book goes into detail on these. Whereas MySQL has only its latest version incorporating them. Not as mature as Firebird's.The core of the book is its Part 5, with several chapters talking about Firebird's SQL variant. The good news is that you should recognise much of it already. Much of your previous SQL experience should carry over to Firebird. Preserves your productivity if you migrate.