并行查询优化器的目标是缩减庞大的计划搜索空间，获得优化的查询规划。
The key problem is how to prune the big search space in order to get an optimized query plan for query parallel optimization.
并行查询执行计划的搜索空间里指数级增长，如何高效地裁剪搜索空间是并行查询优化的关键所在。
The search space of parallel query execution plan is exponential complexity. How to prune the search space efficiently is the key problem of parallel query optimization.
当DB 2优化器为一个查询形成查询访问计划时，它将工作划分到多个数据库分区上，这些数据库分区是并行工作的。
When the DB2 optimizer forms a query access plan for a query, it divides the work among the database partitions which work in parallel.
SQL查询的优化利用了一些复杂的功能，例如：查询重写、多连接(join)方法、详细的统计、并行性等。
The optimization of SQL queries utilize sophisticated features, such as: query rewrite, multiple join methods, detailed statistics, parallelism etc.
查询优化是并行数据库系统的核心技术。
Query optimization is the critical technique of parallel database systems.
查询优化和处理是并行数据库管理系统的关键组成部分。
Query optimization and processing is a critical component of parallel database systems.
这种优化方法大大地缩减了查询执行计划空间，确保了并行查询执行计划的优化性。
This method cuts down query plan search space greatly, thus ensures the quality of parallel query execution plans.
数据流中的查询计划需要不断进行适应性优化，针对该特征提出一种查询计划的并行迁移策略。
This paper presents a new parallel migration strategy for a query plan in order to adapt the continuity of queries and variability of system environment and date itself.
这些算法和相应的查询优化处理器已用于作者自行设计的并行数据库管理系统原型。
A complete set of a algorithms and techniques are proposed. the algorithms and techniques have been used in a prototype parallel database system designed by the author.
多连接查询优化是并行数据库系统的核心问题。
The multi-join query optimization is the critical problem of parallel query optimization in parallel database system.
本文利用数据分片和并行处理策略，提出一种采用直接连接的查询优化算法，能有效地缩减查询处理的响应时间。
This paper presents an optimized query algorithm, which adopts direct-join using data partition and parallel processing. It can reduce the response time of query process.
实践证明，这些技术和方法不仅能够快速有效地实现并行数据库管理系统，也能够有效地进行并行数据库查询的优化和处理。
It is shown by the prototype system that the proposed algorithms and techniques are very efficient and effective for query optimization and...
实践证明，这些技术和方法不仅能够快速有效地实现并行数据库管理系统，也能够有效地进行并行数据库查询的优化和处理。
It is shown by the prototype system that the proposed algorithms and techniques are very efficient and effective for query optimization and...
应用推荐