Beijing OceanBase Technology Co., Ltd.

Storage management by a target node for a distributed database includes sending, except the target node, a block query request to n−1 nodes of n nodes of a distributed jointly using a target memory storing some data blocks. N−1 to-be-reclaimed data block sets are received can combined with a to-be-reclaimed data block set maintained by the target node to obtain a combined data block set which is sent to the n−1 nodes. Each of the n−1 nodes removes a data block from the combined data block set and provides an obtained filtered data block set to the target node. The obtained filtered data block set and an n−1 filtered data block set sent by the n−1 nodes as n target data block sets is used by the target node. An overlapping data block of the n target data block sets is determined. The overlapping data block is reclaimed.

This specification provides a database system, and primary database election methods and apparatuses. The system includes at least one auxiliary node and a plurality of clusters. If any cluster is a primary database of the first table and the other clusters are standby databases: the primary database applies to all auxiliary nodes and all clusters for extension of a term of the primary database during the current term, and if the primary database obtains more than half of approval votes before the current term ends, the primary database determines that the term of the primary database is successfully extended, otherwise, the primary database downgrades itself to a standby database; and the auxiliary node and/or the clusters that don't record the primary database of the first table in term initiate a distributed election, and elect a cluster that obtains more than half of approval votes as a new primary database.

This application relates to the field of communication technologies, and specifically provides a data access method and apparatus, an electronic device, and a storage medium. The data access method includes: when it is determined that a data access request sent by a client is received, obtaining an access control condition for a subnet address segment of a data server, where the subnet address segment is obtained through division from a local area network address segment corresponding to the first VPC, and the client is deployed in a second VPC; generating a data response message based on the data access request if it is determined that the data access request satisfies the access control condition; obtaining a routing table rule for the subnet address segment of the data server; and returning the data response message to the client based on the routing table rule. In this way, a quantity of consumed VPC is reduced while data isolation is ensured.

One or more implementations of this specification provide a data query method and apparatus, including: performing range filtering on pre-constructed index data based on a query condition in a data query instruction and row-stored data in the index data to obtain a first data range; filtering the first data range based on another query condition and column-stored data in the index data to obtain a second data range; and processing data in the second data range based on the data query instruction to obtain a data query result. In the implementations of this specification, row-stored data and column-stored data are pre-constructed, so that in a data query operation, the row-stored data and the column-stored data can be invoked simultaneously, and a data intersection is calculated by using the row-stored data and the column-stored data, to quickly select a queried data range, thereby improving data query efficiency of a database.

One or more implementations of the present specification provide a data processing method and apparatus, an electronic device, and a storage medium. The method includes: in a process of writing target data in a memory into a disk, in response to receiving a query instruction for the target data, separately querying data from at least one piece of first local data and at least one piece of second local data based on the query instruction, intermediate index layer information of the at least one piece of first local data, and intermediate index layer information of the at least one piece of second local data, and sorting the queried data as a data query result. The first local data includes some data stored in the disk in the target data, the second local data includes some data stored in the memory in the target data, the target data is in a column-stored form, and each column group of the target data corresponds to one piece of second local data.

The present application relates to the field of database technologies, and provides a data query method and apparatus, an electronic device, and a storage medium. The data query method includes: obtaining a first query statement to be queried; determining, based on the first query statement, a first data table and a second data table to be used for an inner join operation, a first join column to be used for the inner join operation in the first data table, and a second join column to be used for the inner join operation in the second data table; determining, based on the first query statement, whether the first join column and the second join column satisfy a data pushdown condition; in response to determining that the data pushdown condition is satisfied, updating the first query statement to obtain a second query statement; and performing data query on the first data table and the second data table based on the second query statement, to obtain a data query result. As such, a data table can be first filtered, and then an inner join operation is performed, thereby reducing a data processing amount and improving data query performance.

The present specification provides an outline binding method and apparatus, and a storage medium. The method includes: obtaining a query statement; generating a formatted query statement corresponding to the query statement; determining a target outline that matches the formatted query statement from at least one first-type outline, the first-type outline being a formatted outline to which a plurality of query statements capable of being normalized are jointly bound; and generating a plan corresponding to the query statement by using the target outline. The present specification allows a plurality of query statements to be jointly bound to a formatted outline, thereby implementing binding of a formatted outline without a need to modify service logic, improving flexibility of outline binding, and ensuring correctness and reliability of outline effectiveness.

This specification provides an online evolution method and apparatus for an execution plan, a device, and a storage medium. The method includes: In response to a received current database request including a target database statement, an evolution task is obtained from a plan cache corresponding to the target database statement. A type of an execution plan actually used by the database request is selected, so that an accumulative quantity of execution times of each type of execution plan in an implementation process of the evolution task is positively correlated with performance of each type of execution plan. After the evolution task ends, if it is determined that performance of a current execution plan of an evolution type is better than performance of an execution plan of a baseline type, the execution plan of the evolution type is changed into an execution plan of the baseline type corresponding to the target database statement.

The present application relates to the field of database technologies, and for example provides a data completion method and apparatus, an electronic device, and a storage medium. A data completion method includes: performing area division on a target table to be processed based on a primary key column in the target table to obtain at least one target area; determining a number of rows in each of the at least one target area; determining a starting row offset value of each target area based on the number of rows corresponding to each of the at least one target area; and writing data of each target column group of at least one target column group in the target table and in each target area to a baseline sorted string table corresponding to the target column group based on the starting row offset value of each target area. As such, it is not necessary to create corresponding column indexes for all columns separately, nor to sort data of each column through the column index, thereby simplifying the cumbersome steps of data completion and reducing consumption of system resources and time costs.

This specification discloses example distributed table lock application methods and apparatuses, storage media, and electronic devices. In an example method, a master node receives a data processing request and determines a data table that to-be-processed data corresponding to the data processing request are located in. The master node generates a table lock for the data table; performs a lock operation on the data table and generates lock status information corresponding to the data table; writes the lock status information into a local log of the master node and synchronizes the log to a slave node such that the slave node stores the log. After the master node restarts, determines whether the master node stores the log; and in response to that the master node stores the log, restores the lock operation on the data table based on the lock status information recorded in the log.