Abstract: The present disclosure relates to fault repair methods for a database system. In one example method, when working normally, a master node backs up, to a global buffer pool (GBP) node by using a data transmission protocol with a low latency and a high throughput (for example, a remote direct memory access (RDMA) protocol), a modified page generated because of transaction modification. When the master node is faulty, a standby node does not need to replay all remaining replay logs that are not replayed, but only needs to replay redo logs corresponding to a page that does not exist on the GBP node and pages that are not sequentially arranged and obtain the pages.

Abstract: The present disclosure relates to fault repair methods for a database system. In one example method, when working normally, a master node backs up, to a global buffer pool (GBP) node by using a data transmission protocol with a low latency and a high throughput (for example, a remote direct memory access (RDMA) protocol), a modified page generated because of transaction modification. When the master node is faulty, a standby node does not need to replay all remaining replay logs that are not replayed, but only needs to replay redo logs corresponding to a page that does not exist on the GBP node and pages that are not sequentially arranged and obtain the pages.

Abstract: The present invention provides a database access method, where the method includes the following steps: receiving an access request input by a client, where the access request includes at least one command statement; performing rule matching between the command statement included in the access request and a rule in a preset rule set, and performing transformation processing on a statement that is included in the access request and that matches the rule, so as to generate a sinking statement that satisfies an execution requirement of a data source, where the sinking statement is a statement that is delivered to a database and executed by the data source; and transmitting the sinking statement to the database to which the sinking statement points. The present invention further provides a database access apparatus and a database system to which the foregoing method is applied.

Abstract: The present invention discloses a method and an apparatus for querying data in cross-shard databases. The method includes: receiving a query request; querying statistics information of respective shard databases in which two tables used in an association operation are located; sending, according to the statistics information and the query condition, a driving table query request to a shard database in which a driving table is located, and receiving a first query result set returned by the shard database in which the driving table is located; deduplicating association field values in the first query result set, and sending a result set delivery request and deduplicated association field values to a shard database in which the non-driving table is located; and sending a non-driving table query request to the shard database; and receiving a second query result set returned by the shard database. Efficiency of querying data in cross-shard databases is improved.

Abstract: The present invention provides a database access method, where the method includes the following steps: receiving an access request input by a client, where the access request includes at least one command statement; performing rule matching between the command statement included in the access request and a rule in a preset rule set, and performing transformation processing on a statement that is included in the access request and that matches the rule, so as to generate a sinking statement that satisfies an execution requirement of a data source, where the sinking statement is a statement that is delivered to a database and executed by the data source; and transmitting the sinking statement to the database to which the sinking statement points. The present invention further provides a database access apparatus and a database system to which the foregoing method is applied.

Abstract: The present disclosure discloses an online index rebuilding method and apparatus, where the method includes: receiving an online index rebuilding request; adding a schema shared lock to a data table corresponding to an identifier of the data table; obtaining a latch and obtaining a structure control right of the data table; reserving storage space of a shadow index for an original index, allocating an entry address of the shadow index, and adding the entry address of the shadow index to a root page of the data table; releasing the latch; building the shadow index in the storage space of the shadow index; updating an index entry address on the root page of the data table to the entry address of the shadow index after the latch is obtained again; and releasing the latch obtained again and the schema shared lock. Therefore, efficiency of online index rebuilding is improved.

Abstract: Embodiments provide a data query method and apparatus. The method includes receiving a query request, where the query request includes a query condition, and the query condition relates to N different databases. The method also includes calculating a query cost of each cross-database join processing manner of M cross-database join processing manners, where the query cost of each cross-database join processing manner is a cost for performing, using each cross-database join processing manner, in the N different databases, data query corresponding to the query condition, and M is an integer greater than or equal to 2. The method also includes determining, in the M cross-database join processing manners, a cross-database join processing manner for current use according to the query cost of each cross-database join processing manner, and performing, using the cross-database join processing manner for current use, in the N different databases, data query corresponding to the query condition.

Abstract: The present invention relates to the field of databases, and discloses a computing device and a method for executing a database operation command. In the present invention, whether an operation requested by an operation command is a read operation is determined; and if the operation requested by the operation command is a read operation, the operation command is executed via authorized access to database server process memory and a query result is obtained, thereby improving data reading performance; or if the operation requested by the operation command is not a read operation, the operation command is forwarded to a database server for executing the operation command, thereby improving reliability of a non-read operation.

Abstract: A data synchronization system and method. The method includes that when a change happens in a source application, data is collected from a source application based on a target application subscribing the source application and collection data is transmitted to the target application or is directly inserted to target database. The system includes data collection unit and distribution unit. The present invention may realize synchronization on demand, simultaneously reduce greatly synchronous data quantity, decrease network load, and guarantee smoothness and stabilization of network. The present invention applies to data synchronization of enterprise internal/external data systems, telecommunication networks, etc.

Abstract: A data synchronization system and method. The method includes that when a change happens in a source application, data is collected from a source application based on a target application subscribing the source application and collection data is transmitted to the target application or is directly inserted to target database. The system includes data collection unit and distribution unit. The present invention may realize synchronization on demand, simultaneously reduce greatly synchronous data quantity, decrease network load, and guarantee smoothness and stabilization of network. The present invention applies to data synchronization of enterprise internal/external data systems, telecommunication networks, etc.

Abstract: A method for routing includes upon receipt of a routing analysis request, analyzing a preset routing rule according to the contents in the routing analysis request to obtain the data source information corresponding to the routing rule and routing the contents in the routing analysis request to the data source corresponding to the obtained data source information. An embodiment of the disclosure also provides a system and an apparatus for routing. The method, system, and apparatus provided by embodiments of the present disclosure may improve the routing flexibility and data processing efficiency.