Hitachi, Ltd.

Yasuhiro Tahara

Shinsuke Hamada

Norihiro Hara

Kouji Kimura

A DBMS is configured to identify a Boolean expression and conditional expressions from a search query, and to extract for each of the identified conditional expressions the value of a record ID conforming to a conditional expression. The DBMS is configured to change a conformity result value corresponding to the extracted record ID and conditional expression to a first value signifying conformity, in Boolean expression determination information, which is information that includes a determination set having a record ID value and a plurality of conformity result values respectively corresponding to a plurality of conditional expressions, and, on the basis of the Boolean expression, to perform logical operations on the plurality of conformity result values of a determination set, for each determination set in the Boolean expression determination information.

System, apparatus, and method for executing a query including boolean and conditional expressions

An execution system executes an update batch according to an update batch execution request from a terminal device and gives a batch execution command to each standby system. Each system stores the content of updated data in its update buffer; and subject to termination of the update batch by each system, the post-update data content is reflected in a database. While the above processing is performed, the execution system and the standby systems accept a reference request from the terminal device; and in a case of 'batch not executed' or 'batch in execution', each system searches the database and then returns the pre-update data content to the terminal device; and in a case of &#x201c;update content being reflected&#x201d;, each system searches the database or the update buffer and then returns the post-update data content to the terminal device.

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Tokyo, Japan

Yasuhiro Tahara