Abstract: Implementations of this specification provide methods and apparatuses for generating index entries. One method includes: acquiring a first sequence number of front large object data that is adjacent to a target data to be inserted in a large object data, wherein the first sequence number is generated based on a first code arrangement sequence and is comprised in a first index entry corresponding to the front large object data, in response to determining that the second sequence number immediately following the first sequence number is occupied, determining, based on a second code arrangement sequence, a branch index sequence number for the target data, and adding an index entry comprising the branch index sequence number to an index of the large object data, wherein the index entry is added between the first index entry comprising the first sequence number and a second index entry comprising the second sequence number.

Abstract: An electrode structure of a flow battery. A density of the vertical tow in the electrode fiber is larger than the density of the parallel tow. In the electrode fiber per unit volume, the quantity ratio of the vertical tow to the parallel tow is at least 6:4. The electrode structure includes an odd number of layers of the electrode fibers, and the porosity of other layers is larger than that of the center layer. The electrode structure includes the vertical tows, so that, the contact area between the outer surface of the electrode and the adjacent component is increased and the contact resistance is reduced; the electrode has good mechanical properties; the contact resistance of such structure is reduced by 30%-50%; and the layers of the electrode have different thickness depending on the porosity. After compression, the layers with optimized thickness have a consistent porosity.

Abstract: The present specification describes an adaptive resource allocation method and apparatus. One example method includes determining a request time, an execution time, and a response time corresponding to a service statement executed by the database system during a time period, wherein the request time is a time at which the service statement was executed by the database system, the execution time is an amount of time allocated for execution of the service statement by the database system, and the response time is an amount of time that elapsed between the request time and a time at which execution of the service statement ended; identifying a time segment of the time period based on the request time; determining a service type associated with the service statement; and updating a resource quota for the time segment based on the service type, the execution time, and the response time for the service statement.

Abstract: The present specification describes an adaptive resource allocation method and apparatus. One example method includes determining a request time, an execution time, and a response time corresponding to a service statement executed by the database system during a time period, wherein the request time is a time at which the service statement was executed by the database system, the execution time is an amount of time allocated for execution of the service statement by the database system, and the response time is an amount of time that elapsed between the request time and a time at which execution of the service statement ended; identifying a time segment of the time period based on the request time; determining a service type associated with the service statement; and updating a resource quota for the time segment based on the service type, the execution time, and the response time for the service statement.

Abstract: An electrode structure of a flow battery. A density of the vertical tow in the electrode fiber is larger than the density of the parallel tow. In the electrode fiber per unit volume, the quantity ratio of the vertical tow to the parallel tow is at least 6:4. The electrode structure includes an odd number of layers of the electrode fibers, and the porosity of other layers is larger than that of the center layer. The electrode structure includes the vertical tows, so that, the contact area between the outer surface of the electrode and the adjacent component is increased and the contact resistance is reduced; the electrode has good mechanical properties; the contact resistance of such structure is reduced by 30%-50%; and the layers of the electrode have different thickness depending on the porosity. After compression, the layers with optimized thickness have a consistent porosity.

Abstract: A data modification request for modifying data in a primary database is received at the primary database. Based on the data modification request, second data in the primary database is modified to first data. Based on the data modification request, a first log and a second log are generated, where the first log is a simplified log including the first data and the second log is a complete log including the second data. Persistence processing is performed on the first log. A modification result that corresponds to the data modification request is returned.

Abstract: An electrode structure of a flow battery. A density of the vertical tow in the electrode fiber is larger than the density of the parallel tow. In the electrode fiber per unit volume, the quantity ratio of the vertical tow to the parallel tow is at least 6:4. The electrode structure includes an odd number of layers of the electrode fibers, and the porosity of other layers is larger than that of the center layer. The electrode structure includes the vertical tows, so that, the contact area between the outer surface of the electrode and the adjacent component is increased and the contact resistance is reduced; the electrode has good mechanical properties; the contact resistance of such structure is reduced by 30%-50%; and the layers of the electrode have different thickness depending on the porosity. After compression, the layers with optimized thickness have a consistent porosity.

Abstract: A data modification request for modifying data in a primary database is received at the primary database. Based on the data modification request, second data in the primary database is modified to first data. Based on the data modification request, a first log and a second log are generated, where the first log is a simplified log including the first data and the second log is a complete log including the second data. Persistence processing is performed on the first log. A modification result that corresponds to the data modification request is returned.

Abstract: A same voting time, a same vote counting time, and a same leader node tenure is configured by a host for all nodes. Time configuration information including the same configured voting time, the same vote counting time, and the same leader node tenure, is sent to all the nodes. The nodes are operable to vote during the same voting time, count the number of votes during the same vote counting time, and elect a leader node according to a vote counting result. The nodes are enabled to perform periodic node election according to the same leader node tenure.

Abstract: A data modification request for modifying data in a primary database is received at the primary database. Based on the data modification request, second data in the primary database is modified to first data. Based on the data modification request, a first log and a second log are generated, where the first log is a simplified log including the first data and the second log is a complete log including the second data. Persistence processing is performed on the first log. A modification result that corresponds to the data modification request is returned.

Abstract: An electrode structure of a flow battery, a flow battery stack, and a sealing structure of the flow battery stack, wherein the density of the vertical tow in the electrode fiber is larger than the density of the parallel tow. In the electrode fiber per unit volume, the quantity ratio of the vertical tow to the parallel tow is at least 6:4. The electrode structure is composed of an odd number of layers of the electrode fibers, and the porosity of other layers is larger than the porosity of the center layer.

Abstract: Embodiments provide a data block storage method applied to a database employing an LSM tree. According to the method, data in the 0th layer of the LSM tree is organized in MacroBlocks. When the data in the LSM tree is transferred from an upper layer to a lower layer, the data is transferred to the lower layer in the form of MacroBlocks, so that all layers of the LSM tree are organized in the form of MacroBlocks. When inter-layer data merger is performed, the merger may be performed based on the MacroBlocks, which can avoid rewriting of all data on an entire layer and can effectively reduce disk IO and temporary space consumption. Moreover, as each MacroBlock comprises a plurality of variable-length MicroBlocks, the data may be stored in a storage space in a more compact manner.

Abstract: A same voting time, a same vote counting time, and a same leader node tenure is configured by a host for all nodes. Time configuration information including the same configured voting time, the same vote counting time, and the same leader node tenure, is sent to all the nodes. The nodes are operable to vote during the same voting time, count the number of votes during the same vote counting time, and elect a leader node according to a vote counting result. The nodes are enabled to perform periodic node election according to the same leader node tenure.

Abstract: The present disclosure relates to a data unit reuse method, where data is stored in a data unit in the form of a data block and the data block has a block ID. The method includes: successively reading each data block in a current data unit to search for a first specific data block whose block ID does not conform to a predetermined order; determining whether at least one data block whose block ID conforms to the predetermined order exists after the specific data block in the current data unit; when it exists, determining that the current data unit has been damaged, and when it does not exist, determining that a data block immediately previous to the specific data block is a data end.

Abstract: A same voting time, a same vote counting time, and a same leader node tenure is configured by a host for all nodes. Time configuration information including the same configured voting time, the same vote counting time, and the same leader node tenure, is sent to all the nodes. The nodes are operable to vote during the same voting time, count the number of votes during the same vote counting time, and elect a leader node according to a vote counting result. The nodes are enabled to perform periodic node election according to the same leader node tenure.

Abstract: One example method includes receiving, by the one or more processors, a request to update data stored on a distributed data storage system that comprises a primary server and a plurality of secondary servers, the request comprising data updates; sending, by the one or more processors, an update log instruction to the primary server and the plurality of secondary servers so that each of the primary server and the plurality of secondary servers records a log associated with the request; determining, by the one or more processors, that the log has been recorded; and in response to determining that the log has been recorded, sending, by the one or more processors, a data storage instruction to the primary server and a secondary server of the plurality of secondary servers so that each of the primary server and the secondary server stores the data updates.

Abstract: Embodiments provide a data block storage method applied to a database employing an LSM tree. According to the method, data in the 0th layer of the LSM tree is organized in MacroBlocks. When the data in the LSM tree is transferred from an upper layer to a lower layer, the data is transferred to the lower layer in the form of MacroBlocks, so that all layers of the LSM tree are organized in the form of MacroBlocks. When inter-layer data merger is performed, the merger may be performed based on the MacroBlocks, which can avoid rewriting of all data on an entire layer and can effectively reduce disk TO and temporary space consumption. Moreover, as each MacroBlock comprises a plurality of variable-length MicroBlocks, the data may be stored in a storage space in a more compact manner.

Abstract: The present specification describes an adaptive resource allocation method and apparatus. One example method includes determining a request time, an execution time, and a response time corresponding to a service statement executed by the database system during a time period, wherein the request time is a time at which the service statement was executed by the database system, the execution time is an amount of time allocated for execution of the service statement by the database system, and the response time is an amount of time that elapsed between the request time and a time at which execution of the service statement ended; identifying a time segment of the time period based on the request time; determining a service type associated with the service statement; and updating a resource quota for the time segment based on the service type, the execution time, and the response time for the service statement.

Abstract: One example method includes receiving, by the one or more processors, a request to update data stored on a distributed data storage system that comprises a primary server and a plurality of secondary servers, the request comprising data updates; sending, by the one or more processors, an update log instruction to the primary server and the plurality of secondary servers so that each of the primary server and the plurality of secondary servers records a log associated with the request; determining, by the one or more processors, that the log has been recorded; and in response to determining that the log has been recorded, sending, by the one or more processors, a data storage instruction to the primary server and a secondary server of the plurality of secondary servers so that each of the primary server and the secondary server stores the data updates.

Abstract: The present disclosure relates to a data unit reuse method, where data is stored in a data unit in the form of a data block and the data block has a block ID. The method includes: successively reading each data block in a current data unit to search for a first specific data block whose block ID does not conform to a predetermined order; determining whether at least one data block whose block ID conforms to the predetermined order exists after the specific data block in the current data unit; when it exists, determining that the current data unit has been damaged, and when it does not exist, determining that a data block immediately previous to the specific data block is a data end.