The invention discloses a
query optimization method based on a unified view of a distributed heterogeneous
database. The method comprises the following steps of: configuring the unified view for the distributed heterogeneous
database for external access; effectively decomposing
SQL query statements of the unified view according to a physical table of a
database to be queried so as to maximally reduce the number of accesses; querying corresponding physical table by the decomposed
SQL query statements and returning back
resultant data, wherein a cache region is firstly queried, if the cache region contains corresponding
resultant data, the result is directly obtained, and priorities are set for the
SQL query statements so as to obtain an optimal
result set as much as possible in each time while querying the physical table; and combining the
resultant data returned after querying the physical table, and storing the combined resultant data and the corresponding SQL query statements into the cache region. The
query optimization method based on the unified view of the distributed heterogeneous database improves efficiency for querying the unified view of the distributed heterogeneous database and reduces usage of resource.