Abstract: An active transaction list synchronization method and apparatus comprising a first node that records, in a transaction list incremental log buffer, a transaction list incremental log that is obtained after last active transaction list synchronization, where the transaction list incremental log indicates a change of a transaction recorded in an active transaction list of the first node and includes an added-transaction log and a committed-transaction log, wherein the added-transaction log indicates a transaction is added to the active transaction list, wherein the committed-transaction log indicates a transaction is deleted from the active transaction list. When performing group commit on transactions recorded in the committed-transaction log, the first node sends the transaction list incremental log to at least one second node.

Abstract: A transaction execution method, apparatus, and system is disclosed. The method is applied to a CN of an OLTP cluster database, and the method includes: receiving a page request message sent by a first PN, where the first PN has a first transaction configured, the first transaction includes at least one operation, and the page request message includes an identifier of a to-be-processed page and an identifier of the first PN; if the to-be-processed page indicated by the identifier of the to-be-processed page is the same as a hot page in a preset hot page set, determining a target operation corresponding to the to-be-processed page, where the preset hot page set includes at least one hot page; executing the target operation on the to-be-processed page to obtain an execution result; and sending the execution result to the first PN indicated by the identifier of the first PN.

Abstract: An active transaction list synchronization method and apparatus comprising a first node that records, in a transaction list incremental log buffer, a transaction list incremental log that is obtained after last active transaction list synchronization, where the transaction list incremental log indicates a change of a transaction recorded in an active transaction list of the first node and includes an added-transaction log and a committed-transaction log, wherein the added-transaction log indicates a transaction is added to the active transaction list, wherein the committed-transaction log indicates a transaction is deleted from the active transaction list. When performing group commit on transactions recorded in the committed-transaction log, the first node sends the transaction list incremental log to at least one second node.

Abstract: A multi-version concurrency control method in a database and a database system is presented. The database system sets a data page link of a page, where the data page link includes a page pointer, and a page pointer is used to point to another version page prior to a last operation on the version page. In this way, when a page in the database is read, if a timestamp of a current version page is greater than a timestamp of a read transaction, page-level rollback may be directly performed according to a data page link of the page that is requested to read to roll back to a page that needs to be read, which facilitates queries for data on each version page in the database. Further, the database system may implement record rollback efficiently.

Abstract: A transaction execution method, apparatus, and system is disclosed. The method is applied to a CN of an OLTP cluster database, and the method includes: receiving a page request message sent by a first PN, where the first PN has a first transaction configured, the first transaction includes at least one operation, and the page request message includes an identifier of a to-be-processed page and an identifier of the first PN; if the to-be-processed page indicated by the identifier of the to-be-processed page is the same as a hot page in a preset hot page set, determining a target operation corresponding to the to-be-processed page, where the preset hot page set includes at least one hot page; executing the target operation on the to-be-processed page to obtain an execution result; and sending the execution result to the first PN indicated by the identifier of the first PN.

Abstract: A multi-version concurrency control method in a database and a database system, where the database system sets a data page link of a page, where the data page link includes a page pointer, and a page pointer is used to point to another version page prior to a last operation on the version page. Hence, when a page in the database is read, and when a timestamp of a current version page is greater than a timestamp of a read transaction, page-level rollback may be directly performed according to a data page link of the page that is requested to read to roll back to a page that needs to be read, which facilitates queries for data on each version page in the database, and the database system may implement record rollback efficiently.

Abstract: A data scanning method and apparatus are provided. The method includes analyzing a data scanning condition carried in a received data scanning request and determining at least one target data partition used to store data, acquiring a scanning cost of the target data partition, where the scanning cost includes waiting time of data scanning, allocating the target data partition to a processing resource according to the scanning cost so as to execute parallel data scanning, and acquiring a scanning result returned by the processing resource. In the present invention, statistics information of a data partition is collected, a scanning cost is acquired, and a target-data-partition operation group is appropriately allocated to a processing resource, thereby shortening waiting time of the whole data scanning.

Abstract: The disclosure discloses a transaction processing method, a processing node, and a central node. The method includes: receiving, by the processing node in the cluster, global snapshot information according to a preset time interval, where the global snapshot information includes a transaction identifier of a running transaction in a cluster; storing the received global snapshot information in a cache; and processing the transaction according to the global snapshot information stored in the cache. In the transaction processing method, a central node in a cluster sends latest global snapshot information to each processing node according to a preset time interval, so that the processing node can store the global snapshot information. When applying for global snapshot information during transaction processing, the processing node does not need to obtain latest snapshot information from the central node. Therefore, network overheads can be reduced, and transaction processing efficiency can be improved.

Abstract: Embodiments of the present invention disclose a data restoration method, including: after a transaction is submitted, saving a generated transaction log to a buffer of a current node, and backing up the transaction log to a buffer of at least one backup node except the current node; writing the transaction log saved in the buffer of the current node or the transaction log backed up in the buffer of the backup node into a transaction log file in a disk, where the transaction log file in the disk is used for restoring data of the current node; and restoring, based on the transaction log file in the disk, lost data of the current node when a data loss event occurs in the current node. By means of the present invention, a risk of system data can be reduced, and durability, safety, and reliability of the system data can be improved.

Abstract: A multi-version concurrency control method in a database and a database system, where the database system sets a data page link of a page, where the data page link includes a page pointer, and a page pointer is used to point to another version page prior to a last operation on the version page. Hence, when a page in the database is read, and when a timestamp of a current version page is greater than a timestamp of a read transaction, page-level rollback may be directly performed according to a data page link of the page that is requested to read to roll back to a page that needs to be read, which facilitates queries for data on each version page in the database, and the database system may implement record rollback efficiently.

Abstract: A data processing method and apparatus, which relate to the computer field and are capable of effectively improving scalability of a database system. The data processing method includes: receiving source code of an external routine, where the source code of the external routine is compiled by using an advanced programming language; compiling the source code to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform; converting, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform; and storing the machine code to a database. The data processing method and apparatus provided by the embodiments of the present invention are used to process data.

Abstract: A method, apparatus, and system for storing an execution plan, and relate to the field of databases, which may improve a cache hit rate of an execution plan and reduce system overheads. The method includes sending, by the client, a structured query language (SQL) request and generated location information to the database server, and according to the received SQL request and the received location information, generating and executing, by the database server, an execution plan corresponding to the SQL request, and saving the execution plan to a cache indicated by the location information. The location information may indicate a location of a cache of a client or a cache of a database server.

Abstract: A data processing method and apparatus, which relate to the computer field and are capable of effectively improving scalability of a database system. The data processing method includes: receiving source code of an external routine, where the source code of the external routine is compiled by using an advanced programming language; compiling the source code to obtain intermediate code, where the intermediate code is a byte stream identifiable to a virtual machine on any operating platform; converting, according to an instruction set on the operating platform, the intermediate code into machine code capable of running on the operating platform; and storing the machine code to a database. The data processing method and apparatus provided by the embodiments of the present invention are used to process data.

Abstract: Embodiments of the present invention disclose a data restoration method, including: after a transaction is submitted, saving a generated transaction log to a buffer of a current node, and backing up the transaction log to a buffer of at least one backup node except the current node; writing the transaction log saved in the buffer of the current node or the transaction log backed up in the buffer of the backup node into a transaction log file in a disk, where the transaction log file in the disk is used for restoring data of the current node; and restoring, based on the transaction log file in the disk, lost data of the current node when a data loss event occurs in the current node. By means of the present invention, a risk of system data can be reduced, and durability, safety, and reliability of the system data can be improved.

Abstract: A data scanning method and apparatus are provided. The method includes analyzing a data scanning condition carried in a received data scanning request and determining at least one target data partition used to store data, acquiring a scanning cost of the target data partition, where the scanning cost includes waiting time of data scanning, allocating the target data partition to a processing resource according to the scanning cost so as to execute parallel data scanning, and acquiring a scanning result returned by the processing resource. In the present invention, statistics information of a data partition is collected, a scanning cost is acquired, and a target-data-partition operation group is appropriately allocated to a processing resource, thereby shortening waiting time of the whole data scanning.