Extracting Schema from an OEM Database

While the schema-less feature of the OEM(Object Exchange Modl)gives flexibility 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 th following reatures.(1)In addition to representing th nested label structure of an OEM database,the proposed OEM schema keeps up-tp-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 schems 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).

Extracting schema from an OEM database

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).