Abstract: A database system as well as a method and an apparatus for querying a database are disclosed herein. In one embodiment, a system comprises a master database, at least one slave database, and a query processing unit. The master database has a data connection with the slave database, and the slave database has a data connection with the query processing unit. The query processing unit is configured to split a query request into query operation instructions having non-overlapping query ranges, send the split query operation instructions to the same or different slave databases to perform the query operations, and return the query results. The disclosed embodiments improve query efficiency.

Abstract: Embodiments in the present description provide an operation request processing method and apparatus, and a device, and a readable storage medium, and a system. In the present embodiment, after obtaining an operation request for a data table, a read-write node can return a request processing completion message to a requester in time without waiting for all read-only nodes; a locking operation is performed on the data table, a log of locking the data table is written into a redo log file; and after status information of the log of locking is written into a status record, a monitoring processing process can achieve log playback monitoring of all the read-only nodes by using the status record and the log of locking. Thus, an asynchronous processing mechanism is achieved, and the stability and efficiency of operation request execution are improved.

Abstract: A method including acquiring, by a primary database, in response to a transaction commit request, a log difference between a transaction log of the primary database and a transaction log that has been synchronized to a secondary database; suspending a transaction commit operation if the log difference is greater than a first threshold; and executing the transaction commit operations if the log difference is less than or equal to the first threshold.

Abstract: A database system as well as a method and an apparatus for querying a database are disclosed herein. In one embodiment, a system comprises a master database, at least one slave database, and a query processing unit. The master database has a data connection with the slave database, and the slave database has a data connection with the query processing unit. The query processing unit is configured to split a query request into query operation instructions having non-overlapping query ranges, send the split query operation instructions to the same or different slave databases to perform the query operations, and return the query results. The disclosed embodiments improve query efficiency.

Abstract: A method including acquiring, by a primary database, in response to a transaction commit request, a log difference between a transaction log of the primary database and a transaction log that has been synchronized to a secondary database; suspending a transaction commit operation if the log difference is greater than a first threshold; and executing the transaction commit operations if the log difference is less than or equal to the first threshold.

Abstract: A log fragmentation method is disclosed. A slave database server receives a first log sent by a master database server, wherein the first log includes a data table identifier and match identifier. The slave database server determines a match tree based on the data table identifier of the first log, and fragments the first log based on the match tree. Using a match tree that has been set up, a tree structure of the match tree can be effectively utilized to fragment a log, and the fragmented log has a high degree of concurrency, thus improving the efficiency of log replay.

Abstract: Resource allocation methods and apparatuses are provided, for dynamically allocating resources to multiple processing units that share resources in a same resource allocation unit. One exemplary resource allocation process comprises: determining amounts of data stored on the multiple processing units; and allocating resources to the multiple processing units according to the amounts of data stored on the multiple processing units, more resources being allocated to a processing unit that stores a larger amount of data. The present application can make fuller use of resources.

Abstract: A log fragmentation method is disclosed. A slave database server receives a first log sent by a master database server, wherein the first log includes a data table identifier and match identifier. The slave database server determines a match tree based on the data table identifier of the first log, and fragments the first log based on the match tree. Using a match tree that has been set up, a tree structure of the match tree can be effectively utilized to fragment a log, and the fragmented log has a high degree of concurrency, thus improving the efficiency of log replay.