QUERY OPTIMIZATION METHOD USING INDEX MERGING ON DISTRIBUTED DATABASE

摘要

Provided is a method for generating an index, which is an aggregate of all field data in a column specified in a conditional clause of a query and unique row numbers for accessing a database, to access the database at minimum cost, and to enhance data processing performance through optimized queries. The query optimization method according to an embodiment of the present invention includes: a step for parsing a query in syntax units to extract a condition attribute; a step for generating B+Trees composed of pairs of field values of corresponding columns and corresponding Row Nums by using the extracted condition attribute; a step for arranging the generated B+Trees in ascending order on the basis of the respective field values; and a step for generating only the corresponding rows by means of a query in the B+Trees arranged in ascending order. Accordingly, a unique row number in a table can be used as an access medium to reduce unnecessary access and thereby increase search performance, indexes are internally arranged, thus making it easy to extract a column value of a conditional clause, and unnecessary operations for a changed table can be reduced to generate indexes in a minimal amount of time.