Abstract: A transaction processing method and apparatus, a computer device, and a storage medium, improve transaction processing efficiency. When read and write operations of a target transaction are executed, a concurrent transaction of a target transaction can be obtained and used to determine whether a data anomaly exists based on read-write sets of the concurrent transaction and the target transaction. The read-write sets of the concurrent transaction and the target transaction can be merged to commit the target transaction. In this way, various data anomalies can be comprehensively detected, and data state consistency is ensured. The transaction processing method does not rely completely on locking technology nor on dependency graph technology, thereby preventing system concurrency from being limited, improving querying speed and modification speed of data, and improving transaction processing efficiency.

Abstract: This application discloses a data replication method and apparatus, a computer device, and a storage medium, and belongs to the field of database technologies. The method includes: adding, when a commitment operation of a transaction is detected, historical state data of the transaction to a data queue; adding at least one piece of historical state data in the data queue to a transmission buffer; and replicating, when a first preset condition is met, the at least one piece of historical state data in the transmission buffer to a cluster device. In this application, a node device does not need to convert an original historical state data format into a log format, and the cluster device does not need to parse a log into an original data format for storage, thereby avoiding a cumbersome log replay procedure, and improving the efficiency of the data replication process.

Abstract: In a data read method a plurality of tuples meeting a read condition are determined in a case that the data read request is received and according to a read condition carried in the data read request. Global transaction statuses of a plurality of global transactions corresponding to the plurality of tuples are obtained. Global commit times of the plurality of global transactions according to the global transaction statuses of the plurality of global transactions are obtained. Then a target tuple from the plurality of tuples is determined based on the global commit times of the plurality of global transactions, the target tuple being visible relative to the data read request.

Abstract: A method and system for matching image features is applied to mine machine vision. The method includes de-noising an image, performing super-pixel segmentation to obtain a plurality of image blocks, calculating the information entropy of each image block to obtain an image block with information entropy greater than a first preset threshold, extracting feature points of the image block, to obtain the feature point set of the image, using a wavelet method to describe the feature points in the feature point set to obtain a feature point descriptor set, and matching feature points in the feature point set with the feature points of a target image.

Abstract: This application discloses a data processing method and apparatus, a storage medium and an electronic device. The method includes: obtaining, by the electronic device, at least one target row to be cleared at a target time from a data table of a row-oriented database; storing target attribute values recorded in the at least one target row to target pages in a column-oriented database; and clearing the at least one target row after the target time arrives. The application resolves the technical problem that it is difficult to trace historical data in the related data processing technology.

Abstract: This application provides a log execution method and apparatus, a computer device and a storage medium and relates to the technical field of databases. The method includes circularly scanning a log execution active window, the log execution active window comprising a plurality of logs which are not executed, and all the logs before the log execution active window having been executed; acquiring a conflict verification result of a log in the log execution active window based on storage range information of the log, the storage range information indicating a storage range of the log and a storage range of a target number of logs before the log, and the target number being equal to a size of the log execution active window; and executing the log if the conflict verification result is no conflict.

Abstract: An electronic device determines a concurrent transaction of a target transaction. The concurrent transaction and the target transaction include a read and write operation acting on a same variable, and the target transaction is a transaction to be committed. The device obtains a first intersection between a read set of the target transaction and a write set of the concurrent transaction. The device obtains a second intersection between a write set of the target transaction and a read set of the concurrent transaction. When at least one of the first intersection and the second intersection is a non-empty data set and the target transaction conflicts with the concurrent transaction, the device determines, based on a version change count of the same variable on which the target transaction and the concurrent transaction act and a target variable list, a data anomaly type the target variable list including the same variable on which the target transaction and the concurrent transaction act.

Abstract: This application discloses a transaction processing method and apparatus, a computer device, and a storage medium, and relates to the technical field of databases. The method includes: obtaining a read set and a write set of a target transaction in response to a read-write operation of the target transaction; determining a logical begin time and a logical end time of the target transaction in response to a validation instruction of the target transaction; updating the logical begin time based on the write set in response to the logical begin time and the logical end time conforming to a concurrent consistency level of the target transaction, to obtain an updated logical begin time; and committing the target transaction in response to the updated logical begin time being less than or equal to the logical end time.

Abstract: In response to an allocation request of a target transaction, transaction allocation indexes respectively corresponding to the at least two node devices are determined. A coordinator node device of the target transaction in the at least two node devices is determined based on the transaction allocation indexes respectively corresponding to the at least two node devices. The coordinator node device coordinates the target transaction. Each coordinator node device coordinates a transaction as a decentralized device so that the transaction can be processed across nodes, which is conducive to improving efficiency of transaction processing, reliability of transaction processing, and system performance of a database system.

Abstract: A data recovery method is provided. In the method, a backup type of a backup data packet is identified. Data recovery is performed based on physically backed up data in the backup data packet in a case that the identified backup type is a hybrid backup, the hybrid backup being a backup process that includes a physical backup and a logical backup. Data recovery is performed on logically backed up data in the backup data packet after the data recovery based on the physically backed up data is completed.

Abstract: This application discloses a database transaction processing method performed by a computer device. The method includes: in a case of starting a target transaction, obtaining, by a working node in a distributed database system, a transaction timestamp of the target transaction and current global latest version information, the target transaction including at least one operation statement for a target data object, and the global latest version information being version information of latest generated metadata of metadata stored in the distributed database system; determining latest-version metadata of the target data object according to the current global latest version information, and determining to-be-accessed user data of the target transaction according to the transaction timestamp; and executing an operation statement of the target transaction on the to-be-accessed user data based on the latest-version metadata of the target data object.

Abstract: A transaction processing method and apparatus, a computer device, and a storage medium, improve transaction processing efficiency. When read and write operations of a target transaction are executed, a concurrent transaction of a target transaction can be obtained and used to determine whether a data anomaly exists based on read-write sets of the concurrent transaction and the target transaction. The read-write sets of the concurrent transaction and the target transaction can be merged to commit the target transaction. In this way, various data anomalies can be comprehensively detected, and data state consistency is ensured. The transaction processing method does not rely completely on locking technology nor on dependency graph technology, thereby preventing system concurrency from being limited, improving querying speed and modification speed of data, and improving transaction processing efficiency.

Abstract: This application discloses a data storage method and associated server, and a non-transitory computer readable storage medium, and belongs to the field of data processing technologies. The method includes: determining historical-state data of a to-be-dumped data item from a database, and determining a service requirement of the historical-state data; determining a target storage format of the historical-state data according to the service requirement; and dumping the historical-state data according to the target storage format.

Abstract: The embodiments of this application provide an uncorrelated subquery optimization method and apparatus, and a storage medium. The method includes determining whether there is an uncorrelated subquery statement in a target clause in a database query statement. In response to the determination that there is the uncorrelated subquery statement in the target clause in the database query statement, the method includes obtaining an estimated number of rows of an execution result set corresponding to the target clause; and determining whether the estimated number of rows is less than a preset threshold. In response to the determination that the estimated number of rows is less than a preset threshold, the method includes executing the uncorrelated subquery statement, and rewriting the target clause according to an execution result set of the uncorrelated subquery statement, to eliminate the uncorrelated subquery statement.

Abstract: A data processing method is provided. The method includes obtaining an operation instruction, the operation instruction including operation type information and target data unit information corresponding to a target data unit; querying a target data group in a data group set according to the target data unit information, the data group set including at least one data group, the data group including at least one data unit; obtaining locked-state information of the target data group; performing locking detection on the target data unit based on the locked-state information and the operation type information to obtain a detection result; performing locking processing on the target data unit based on the detection result; and executing the operation instruction after the locking processing is performed, to perform an operation corresponding to the operation type information on the target data unit.

Abstract: A method and system for matching image features is applied to mine machine vision. The method includes de-noising an image, performing super-pixel segmentation to obtain a plurality of image blocks, calculating the information entropy of each image block to obtain an image block with information entropy greater than a first preset threshold, extracting feature points of the image block, to obtain the feature point set of the image, using a wavelet method to describe the feature points in the feature point set to obtain a feature point descriptor set, and matching feature points in the feature point set with the feature points of a target image.

Abstract: In a data read method a plurality of tuples meeting a read condition are determined in a case that the data read request is received and according to a read condition carried in the data read request. Global transaction statuses of a plurality of global transactions corresponding to the plurality of tuples are obtained. Global commit times of the plurality of global transactions according to the global transaction statuses of the plurality of global transactions are obtained. Then a target tuple from the plurality of tuples is determined based on the global commit times of the plurality of global transactions, the target tuple being visible relative to the data read request.

Abstract: This application discloses a data replication method and apparatus, a computer device, and a storage medium, and belongs to the field of database technologies. The method includes: adding, when a commitment operation of a transaction is detected, historical state data of the transaction to a data queue; adding at least one piece of historical state data in the data queue to a transmission buffer; and replicating, when a first preset condition is met, the at least one piece of historical state data in the transmission buffer to a cluster device. In this application, a node device does not need to convert an original historical state data format into a log format, and the cluster device does not need to parse a log into an original data format for storage, thereby avoiding a cumbersome log replay procedure, and improving the efficiency of the data replication process.

Abstract: Aspects of this disclosure provide a data backup method and apparatus, a server, and a non-transitory computer-readable storage medium, belonging to the field of data database technologies. The method can include receiving a backup task that is used for backing up a data item of a target data table. The method can further include obtaining a first snapshot difference between a first historical transaction snapshot and a second historical transaction snapshot when a backup time of the backup task is a historical time period. The first historical transaction snapshot and the second historical transaction snapshot can be transaction snapshots respectively located at a start moment and an end moment of the historical time period. Additionally, the method can include performing the backup task based on the first snapshot difference to obtain backup data including at least a visible version of the data item in the target data table.

Abstract: A data recovery method is provided. In the method, a backup type of a backup data packet is identified. Data recovery is performed based on physically backed up data in the backup data packet in a case that the identified backup type is a hybrid backup, the hybrid backup being a backup process that includes a physical backup and a logical backup. Data recovery is performed on logically backed up data in the backup data packet after the data recovery based on the physically backed up data is completed.