Abstract: Methods and computer systems for storing a query plan in a cache are provided. The method can include: determining a use frequency of the query plan; determining a target storage layer for storing the query plan based on the determined use frequency, wherein the cache includes at least two storage layers and each of the storage layers is associated with a compression level of query plans; processing the query plan according to the compression level of the target storage layer; and storing the processed query plan in the target storage layer.

Abstract: A method including receiving a query request sent by a client; determining resource occupation information of a data set corresponding to the query request; if determining, according to the resource occupation information, to cache the query request, then acquiring the data set corresponding to the query request, and storing the data set in an external memory; and reading the data set from the external memory and sending the data set to the client. By using the method, returning multiple data sets to a client within a short period of time is avoided, thus reducing the occupation of CPU resources, memory resources and network resources, avoiding client query timeout or failure, and improving the usage experience of uses.

Abstract: Data storage and query method and device are disclosed, which facilitate a quick acquisition of query results through index queries at subsequent stages by establishing indexes for columns of a table. Furthermore, by scanning data in the table to obtain statistical information of data in the columns, this facilitates using the statistical information of the data in the columns to perform cost estimation in subsequent queries, in an attempt to obtain a data query mode that has the least cost and the best performance, thus improving query efficiency.

Abstract: The methods and computer systems for storing a query plan in a cache. The method can include: determining a use frequency of the query plan; determining a target storage layer for storing the query plan based on the determined use frequency, wherein the cache includes at least two storage layers and each of the storage layers is associated with a compression level of query plans; processing the query plan according to the compression level of the target storage layer; and storing the processed query plan in the target storage layer.

Abstract: Embodiments of the present application provide a task allocation method and system. The method includes: analyzing at least one query pattern of a target task to acquire expected response time of the query pattern; estimating system cost information and estimated response time according to the query pattern and service description information; estimating node cost information of each processing node of a set of processing nodes in a computing system; selecting a processing node of the set of processing nodes according to the node cost information to allocate subtasks of the target task to the selected processing node; and determining an unallocated subtask in the target task to schedule the unallocated subtask according to the expected response time, the system cost information, and the estimated response time.

Abstract: A method including receiving a query request sent by a client; determining resource occupation information of a data set corresponding to the query request; if determining, according to the resource occupation information, to cache the query request, then acquiring the data set corresponding to the query request, and storing the data set in an external memory; and reading the data set from the external memory and sending the data set to the client. By using the method, returning multiple data sets to a client within a short period of time is avoided, thus reducing the occupation of CPU resources, memory resources and network resources, avoiding client query timeout or failure, and improving the usage experience of uses.

Abstract: Data storage and query method and device are disclosed, which facilitate a quick acquisition of query results through index queries at subsequent stages by establishing indexes for columns of a table. Furthermore, by scanning data in the table to obtain statistical information of data in the columns, this facilitates using the statistical information of the data in the columns to perform cost estimation in subsequent queries, in an attempt to obtain a data query mode that has the least cost and the best performance, thus improving query efficiency.

Abstract: Embodiments of the present disclosure can provide a method and an apparatus for data hierarchical storage. The method comprises: storing one or more data files in a remote disk; acquiring, from the remote disk, a data file of the one or more data files, the data file being last accessed by a user; segmenting the data file into data blocks; caching the data blocks into a local disk; and caching the data blocks from the local disk to a local memory.

Abstract: A method and an apparatus for processing a retransmission request in distributed computing are disclosed. The method includes obtaining a retransmission request to be processed in distributed computing; determining a target copy partition corresponding to the retransmission request based on respective partition response time information of individual copy partitions; sending the retransmission request to the target copy partition. Compared with existing technologies, the present disclosure distinguishes each partition with one another based on a partition response time of the respective copy partition to determine a target copy partition corresponding to a retransmission request, thus selecting a copy with a better response time during retransmission, reducing a response time for the retransmission request and reducing an overall load of an associated cluster.

Abstract: Embodiments of the present application provide a task allocation method and system. The method includes: analyzing at least one query pattern of a target task to acquire expected response time of the query pattern; estimating system cost information and estimated response time according to the query pattern and service description information; estimating node cost information of each processing node of a set of processing nodes in a computing system; selecting a processing node of the set of processing nodes according to the node cost information to allocate subtasks of the target task to the selected processing node; and determining an unallocated subtask in the target task to schedule the unallocated subtask according to the expected response time, the system cost information, and the estimated response time.

Abstract: A method and an apparatus for processing a retransmission request in distributed computing are disclosed. The method includes obtaining a retransmission request to be processed in distributed computing; determining a target copy partition corresponding to the retransmission request based on respective partition response time information of individual copy partitions; sending the retransmission request to the target copy partition. Compared with existing technologies, the present disclosure distinguishes each partition with one another based on a partition response time of the respective copy partition to determine a target copy partition corresponding to a retransmission request, thus selecting a copy with a better response time during retransmission, reducing a response time for the retransmission request and reducing an overall load of an associated cluster.