Duplex structure of main-memory DBMS using log information in diskless environment and method for controlling consistency of data of main-memory DBMS

A method for controlling consistency of data of a memory databases in a duplex structure of a main-memory DBMS (DataBase Management System) having a standby-side DBMS and an active-side DBMS through a network in a system environment without a secondary storage device such as a disk, comprising the steps of:

• a) creating at least one log record on a transaction-by-transaction basis if a query processor of the active-side DBMS receives a update command from a user, obtaining at least one log page allocated from a log pool, connecting the log page to a transaction table, storing the log record in the log page, and changing data of a corresponding database portion;
• b) transmitting the log record to the standby-side DBMS if the transaction is committed, returning the allocated log page to the log pool, and terminating the transaction;
• c) obtaining at least one log page allocated from a log pool if the standby-side DBMS receives the log record from the active-side DBMS, connecting the log page to a transaction table, and storing the received log record in the log page;
• and
• d) transmitting a result of the reception to the active-side DBMS after storing the log record, and changing a memory database using the stored log record.

A computer-readable recording medium in a duplex computer, the recording medium recording a program to perform the functions of:

• a) creating at least one log record on a transaction-by-transaction basis if a query processor of the active side receives a update command from a user, obtaining at least one log page allocated from a log pool, connecting the log page to a transaction table, storing the log record in the log page, and changing data of a corresponding database portion;
• b) transmitting the log record to the standby side if the transaction is committed, returning the allocated log page to the log pool, and terminating the transaction;
• c) obtaining at least one log page allocated from a log pool if the standby side receives the log record from the active side, connecting the log page to a transaction table, and storing the received log record in the log page;
• and
• d) transmitting a result of the reception to the active side after the log record is stored in the standby side, and updating a memory database using the stored log record.