Data Access Language

Data Access Language, or simply DAL, was a SQL-like language parser released by Apple in 1990 to provide unified client/server access to database management systems. It was marginally supported in an on-and-off fashion until the mid-90s, when management apparently grew bored of it and sold it off.

DAL started as a 3rd party product, CL/1 (Connectivity Language One), from a small vendor, Network Innovations. Apple purchased the company in 1988, about the time that client/server databases were becoming a hot issue in the industry. They released their first version of the re-branded software in 1989, for MVS, and followed with other versions over the next year or so.

DAL suffered from most Apple problems of the early 1990s, notably a alternating level of support in which Apple would present the product and then ignore it. DAL's release was also coincident with Apple's fall from grace in the business world, and not coincidentially with Microsoft's ODBC efforts. It appears to have seen little use, and eventually Apple sold it to Independence Technologies in 1994, during a sell-off of a number of "high-end" packages such as an X.400 server. In 1995 BEA Systems bought the company, and in turn sold it to UniPrise in late 1996. During this period it was basically a dead product.

DAL was essentially a cut-down version of SQL, supporting only the most basic functionality, but adding clean syntax for cursor operations, logic, and loops. When sent a command the DAL interpreter broke down the statement and re-built it into subqueries for the underlying data sources. This translation took place on the server-side, unlike most similar tools, requiring a fairly expensive "adaptor" program of dubious performance. This bit of architechture made DAL considerably less appealing that similar systems like ODBC, where the translation normally takes place on the client side and is typically "free".

On the client end, DAL was originally accessed directly through a "system extension", but DAL was later rolled into a single ODBC-like driver layer, Data Access Manager. One of the more common clients was HyperCard. The combination of HyperCard and DAL presented a serious challenge to existing vendors who could offer nothing with a GUI, and soon Oracle purchased a HyperCard-clone, PLUS from Spinnaker Software, to produce Oracle Card.