当一个查询提交客户站点，首先使用元数据字典对查询进行转换，将它转换成相应异种站点上的查询。
When a query is posed to a client site, a metadata dictionary is used to translate the query into queries appropriate for the individual heterogeneous sites involved.
探讨了完备的交通事故信息数据库的内容构成，认为应包括空间数据库、影响因素数据库以及元数据和数据字典库三大部分；
The contents of a perfect traffic accident information spatial-database should include three parts, i. e. spatial-database, influential factors database and database of metadata and data dictionary.
探讨了完备的交通事故信息数据库的内容构成，认为应包括空间数据库、影响因素数据库以及元数据和数据字典库三大部分；
The contents of a perfect traffic accident information spatial-database should include three parts, i. e. spatial-database, influential factors database and database of metadata and data dictionary.
应用推荐