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Programming languages that natively and seamlessly allow objects to continue existing after the program has been closed down are called persistent programming languages. JADE is one such language. A persistent programming language is a programming language extended with constructs to handle persistent data. It is distinguished from embedded SQL in at least two ways: In a persistent programming language: * The query language is fully integrated with the host language and both share the same type system. * Any format changes required between the host language and the database are carried out transparently. In Embedded SQL: * Where the host language and data manipulation language have different type systems, code conversion operates outside of the OO type system, and hence has a higher chance of having undetected errors. * Format conversion must be handled explicitly and takes a substantial amount of code. Using Embedded SQL, a programmer is responsible for writing explicit code to fetch data into memory or store data back to the database. In a persistent programming language, a programmer can manipulate persistent data without having to write such code explicitly. The drawbacks of persistent programming languages include: * While they are powerful, it is easy to make programming errors that damage the database. * It is harder to do automatic high-level optimization. * They do not support declarative querying well. ==See also== * Object-relational mapping * Object-oriented database management systems * Object prevalence 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Persistent programming language」の詳細全文を読む スポンサード リンク
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