In IMS／VS,the collection of macro parameter statements that describes an IMS／ VS data base. These statements describe the hierarchical structure, IMS／VS organization, device type, segment length, sequence fields, and alternate search fields. The statements are assembled to produce data base description blocks.; 在IBM的信息管理系統(tǒng)IMS／VS中,描述IMS／VS數(shù)據(jù)庫的宏參數(shù)語句的集合。這些語句描 述層次結(jié)構(gòu)、IMS／VS組織、設(shè)備類型、段長、順序字段和替換檢索字段。這些語句經(jīng)匯編 后產(chǎn)生數(shù)據(jù)庫描述塊。