Method and apparatus for reducing data locking time by removing a lock when journal data is written into a main memory journal queue
First Claim
1. An on line transaction processing method comprising the steps of:
- requesting to update data on a data base having a plurality of data files which must not be inconsistent;
executing, in response to said requesting step, operations of reserving an exclusive occupation for a piece of data, updating the data and collecting a journal on updating of the data on a plurality of pieces of data, constituting one transaction, on said plurality of data files in sequence;
storing the journal collected in said executing step in a unit of transactions into a volatile memory;
releasing the exclusive occupation of the data related to the transaction in which the journal is stored into the volatile memory during said storing step;
writing the journals stored in said storage step to a non-volatile journal file in the unit of transactions after releasing of the exclusive occupation of the data; and
writing updated data to said data files for transactions whose journals have been written to said non-volatile journal file, and outputting a message on updated data.
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Accused Products
Abstract
A data management system, which is equipped with a data file and a journal file and adapted to reserve the exclusive occupation for data and then update the data, is characterized by releasing the exclusive occupation of data prior to writing of a journal to the journal file and of corresponding updated data to the data file. When data on a data base is updated, the exclusive occupation states of data to be updated are reserved first and then updating of the data is executed on a data buffer placed on a main memory and journals on the updating of the data are collected. The collected journals are entered into a first-in first-out journal queue in units of transactions. The exclusive occupation states of data on a corresponding transaction is released after corresponding journals have been stored in the journal queue. The journals stored in the journal queue are written to the journal file in units of transactions in the order in which they are entered into the queue. Subsequently updated data is written to the data file. The data in the data file is restored using the journal file when a system failure occurs in the data base.
48 Citations
20 Claims
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1. An on line transaction processing method comprising the steps of:
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requesting to update data on a data base having a plurality of data files which must not be inconsistent; executing, in response to said requesting step, operations of reserving an exclusive occupation for a piece of data, updating the data and collecting a journal on updating of the data on a plurality of pieces of data, constituting one transaction, on said plurality of data files in sequence; storing the journal collected in said executing step in a unit of transactions into a volatile memory; releasing the exclusive occupation of the data related to the transaction in which the journal is stored into the volatile memory during said storing step; writing the journals stored in said storage step to a non-volatile journal file in the unit of transactions after releasing of the exclusive occupation of the data; and writing updated data to said data files for transactions whose journals have been written to said non-volatile journal file, and outputting a message on updated data.
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2. A data management system comprising:
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reserving means for reserving an exclusive occupation state for data; updating means for updating data whose exclusive occupation is reserved and collecting a journal; volatile memory means for storing said journal collected by said updating means; releasing means for releasing the exclusive occupation of the data after the storage of said journal to said volatile memory means; and means for writing said journal stored in said volatile memory means to a non-volatile journal file after the releasing of the exclusive occupation of the data by said releasing means. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10)
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11. A data management system equipped with a data file and a non-volatile journal file and adapted to reserve exclusive occupation of data and then update the data, comprising:
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access means for reserving exclusive occupation of data on which a request is made, executing updating of the requested data in a data buffer placed on a main storage device and collecting one or more journals; releasing means for storing the journals collected by said access means in a volatile first-in first-out journal queue in a unit of each transaction and releasing the exclusive occupation of data after the completion of the storing of the journals in the volatile journal queue; journal writing means for writing the journals stored in the volatile journal queue for each said transaction into the non-volatile journal file in the order in which the journals are stored in the volatile journal queue; and data writing means for writing into the data file updated data of the data buffer into the data file for each said transaction whose journals have been written in to the non-volatile journal file. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification