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 invention provide an index establishment method and device. The method can include determining, according to index status information of a column in a database within a preset time threshold, whether an index is to be established for the column; determining an index type according to the data information of the column; and establishing the index for the column according to the index type based on the determination that the index is to be established for the column.

Abstract: This application generally relates to data processing methods and apparatus. One data processing method disclosed herein comprises: creating a Writable Snapshot based on data modification; creating a plurality of Read-Only (“RO”) Snapshots by cloning the Writable Snapshot at distinct predetermined creation-times; receiving a data inquiry request; and conducting the data inquiry through indexing, in a RO Snapshot with a latest creation-time. This approach achieves separation of data modification and data inquiry, enabling efficient real-time updating. Further, by fast indexing and invert indexing, inquiry efficiency is further improved. Additionally, data is stored in data columns, wherein each column may be divided into multiple data blocks according to a fixed block size, and each data block has a same length.

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 evaluating a partition in a database. The method can include: acquiring meta information of a data partition in the database, wherein the meta information comprises an area range value of the data partition; and determining whether the data partition is a valid partition according to a query condition of a query associated with the data partition and the meta information of the data partition.

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: Embodiments of the present invention provide an index establishment method and device. The method can include determining, according to index status information of a column in a database within a preset time threshold, whether an index is to be established for the column; determining an index type according to the data information of the column; and establishing the index for the column according to the index type based on the determination that the index is to be established for the column.

Abstract: This application generally relates to data processing methods and apparatus. One data processing method disclosed herein comprises: creating a Writable Snapshot based on data modification; creating a plurality of Read-Only (“RO”) Snapshots by cloning the Writable Snapshot at distinct predetermined creation-times; receiving a data inquiry request; and conducting the data inquiry through indexing, in a RO Snapshot with a latest creation-time. This approach achieves separation of data modification and data inquiry, enabling efficient real-time updating. Further, by fast indexing and invert indexing, inquiry efficiency is further improved. Additionally, data is stored in data columns, wherein each column may be divided into multiple data blocks according to a fixed block size, and each data block has a same length.

Abstract: A technique for verifying the consistency of slice allocation metadata includes accessing, from user space of an operating system running on the data storage apparatus, a set of drivers running in kernel space of the operating system to obtain slice allocation metadata from the set of drivers, and identifying discrepancies in slice allocation metadata returned from the set of drivers on a per-file-system basis.