First,we dynamically collected statistical information over query windows,and then we continuously optimized query planning by mathematical means.

This paper presents a new parallel migration strategy for a query plan in order to adapt the continuity of queries and variability of system environment and date itself.

Aiming at how the DBMS query optimizer to generate the smallest cost query plan,optimization rules of the relational algebra expression are given.

The heterogeneous data integration systems witness a rapid increase in the number of structured and unstructured data sources that are available online, which can be full-fledged databases, simple files, HTML pages or specialized data sources that posses diverse query processing capabilities, making it difficult for query planning.

Then information integration process, global query processing and query planning are explained in detail.

Three-dimensional visualization and spatial query and analysis of result of image geological logging;

Research on heterogeneous spatial data system query decomposition algorithm;

An approach of global query decomposition that the global queries were transformed into middl.

A CORBA-based architecture, a method of schema integration, a query decomposition algorithm and algorithms of query optimization were brought forward which fit integration of heterogeneous data.