Log-structured database system query processing method and device

A technology for querying request messages and processing methods, which is applied in the database field and can solve problems such as difficulty in ensuring data consistency and lack of concurrency control mechanisms
CN104657364AActive Publication Date: 2015-05-27HUAWEI TECH CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
HUAWEI TECH CO LTD
Publication Date
2015-05-27

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Abstract

A query request message processing method and device for a log-structured data base system, the method comprising: receiving a query request message comprising a primary key of a tuple to be queried and a transaction identifier of the current transaction; according to the query request message, obtaining from the tuple containing the primary key, and satisfying a first specified rule, a tuple with the latest timestamp as the query result; and returning the query result. In order to enable a log-structured database to support transactions and achieve concurrent control, the present invention starts with the query process of a transaction, differentiates the submitted tuples from the tuples not submitted, and at the same time further checks whether the tuples not submitted are being processed by a current transaction, thus preventing the current transaction from finding the tuples being processed by other transactions, achieving isolation of various transactions, and further ensuring the support of transactions by the log-structured database system, and concurrent execution of all transactions without affecting each other.
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Description

technical field

[0001] Embodiments of the present invention generally relate to database technologies, and in particular, relate to a method and device for processing query request messages in a log-structured database system. Background technique

[0002] A tuple is a common concept in database systems, referring to a record in a database table. A tuple can have multiple versions, and the versions are associated by a primary key. A log-structured database system is a database system that stores tuples in a log-like form. In a log-structured database system, when a tuple is added or modified, the new tuple or the new value of the tuple will be appended to the new location instead of modifying the original version of the persisted tuple; when the tuple is deleted, The delete action is identified by a tuple version in a special format (such as adding a delete marker). When reading data, if the delete marker is found, the tuple will be automatically filtered.

[0003] Due to...

Claims

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