The system contains four main components : a feature acquisition module, a query manager, a search engine and a hash table. 系统包括四个主要部分:特征获取模块,查询管理模块,搜索引擎和一个散列表。
Query manager can break down a query, which is generated over the integrated schema by users, based on the connection and configuration information of system and dispatch them to the individual data sources. 用户通过查询处理器建立基于集成模式的查询,系统根据连接信息和配置信息把对集成模式的查询分解成对每个数据源的子查询。
The distributed database middleware is composed of load balancing manager, query processing manager and transaction manager. Distributed storage adopts horizontal distribution placement to store and position record. 分布式数据库中间件包括负载均衡管理器、查询执行器、事务管理器,分别提供对负载均衡、分布式查询、分布式事务的支持。
As an assistant module, the query rewriting index manager is in charge of constructing and maintaining a multi-pass tree which can index all the available materialized views for the convenience of the realization of query rewriting selection method. 查询重写索引管理器作为一个辅助模块,其作用在于将系统中的有效物化视图组织起来构造成为一棵多路搜索二叉树,以便于物化视图查询重写搜索算法的实现。
This also means that an API must be available to query the human task manager for tasks available to a specific user. A task can have at least three different states. 这也意味着,为了查询某一用户可用的任务,必须有可用的API来查询任务管理器,任务至少具有三个不同的状态。