%0 Journal Article
%T Extracting schema from an OEM database<br>Extracting Schema from an OEM Database
%A Shen Yidong
%A <br>Shen
%A Yidong
%J 计算机科学技术学报
%D 1998
%I 
%X While the schema-less feature of the OEM (Object Exchange Model) gives fiexibility in representing semi-structured data, it brings difficulty in formulating database queries.Extracting schema from an OEM database then becomes an important research topic.This paper presents a new approach to this topic with the following features. (1) In addition to representing the nested label structure of an OEM database, the proposed OEM schema keeps upto-date information about instance objects of the database.The object-level information is useful in speeding up query evaluation. (2) The OEM schema is explicitly represented as a label-set, which is easy to construct and update.(3) The OEM schema of a database is statically built and dynamically updated. The time complexity of building the OEM schema is linear in the size of the OEM database.(4) The approach is applicable to a wide range of areas where the underlying schema is much smaller than the database itself (e.g. data warehouses that are made from a set of heterogeneous databases).
%K Data integration
%K OEM data model
%K OEM schema<br>目标交换数据库
%K 数据模型
%K OEM图解
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=8240383F08CE46C8B05036380D75B607&jid=F57FEF5FAEE544283F43708D560ABF1B&aid=823F7DD82960306830B4DAEA2A6EE5BF&yid=8CAA3A429E3EA654&vid=FC0714F8D2EB605D&iid=E158A972A605785F&sid=F50A8B5513721E1C&eid=BF112261B65CB9C9&journal_id=1000-9000&journal_name=计算机科学技术学报&referenced_num=1&reference_num=8