存取路径

IBM并没有发布优化器如何确定最佳存取路径的真正和深入的详细信息，但优化器是一个基于成本的优化器。

IBM does not publish the actual , in-depth details of how the optimizer determines the best access path , but the optimizer is a cost-based optimizer .

让DBMS确定到数据的最优存取路径解除了程序员肩上沉重的负担。

Having the DBMS determine the optimal access path to the data lifts a heavy burden off the programmer 's shoulders .

因为到DB2数据的物理存取路径并不是由程序员在应用程序中编码的，而是由DB2生成的，所以这种情况是完全有可能发生的。

This is all possible because the physical access paths to DB2 data are not coded by programmers in application programs , but are generated by DB2 .

您还需要学习如何最好地编写这些SQL语句以及如何发现DB2选择的存取路径来满足您的SQL请求。

You 'll also need to learn how best to write these SQL statements , and how to discover the access paths DB2 chose to satisfy your SQL requests .

DAFS通过远程直接内存内存传送技术，能有效地缩短数据存取路径，实现更快速的数据存取，从而有效地改善数据存取速度性能。

DAFS can make it possible to shorten data access path effectively through RDMA technology , make data access faster and improve the access speed performance in NAS appliance .

基于事务处理的B+树存取路径的实现

Implementation of B + tree access path based-on transaction processing

泛关系模型的目的在于获得完全的存取路径独立性。

The universal relation model aims at achieving the complete access path independence .

这些数据导航指令叫作存取路径。

These data-navigational instructions are called access paths .

一种内存数据库存取路径的实现方法

A Realization Method for the MMDB Access Path

优化器用排序堆大小来确定存取路径。

The sort heap size is used by the optimizer in determining access paths .

它如何选择在优化存取路径中使用这些策略中的哪一个？

How does it choose which of these strategies to use in the optimized access paths ?

这意味着优化器将始终尝试为每个查询制定减少总体成本的存取路径。

This means the optimizer will always attempt to formulate an access path for each query that reduces overall cost .

在计划优化模块中，详细讨论了存取路径的选择和代价评估的计算方法。

In plan optimization module , the access path selection and the account method of cost evaluation are discussed in detail .

优化器使用该数据模型来估计可以用于解决某个特定查询的其它存取路径的成本。

This data model is used by the optimizer to estimate the costs of alternative access paths that can be used to resolve a particular query .

参数化查询的主要性能好处是优化器可以制定在重复执行语句时能够再使用的存取路径。

The key performance benefit of parameterized queries is that the optimizer can formulate an access path that can be reused over repeated executions of the statement .

本文对数据库的查询技术进行分析，给出两种优化方法：分解查询和选择最优存取路径。

In this paper , first the query technology on database is analysed , then two optimization methods are offered : the disintegration query and the best access path selection .

此外，数据库可以更好地理解它存储的数据的状态，从而可以生成到数据的更有效和动态的存取路径。

In addition , the database can have a better understanding of the state of the data it stores , and thereby can produce a more efficient and dynamic access path to the data .

在查询优化模块，介绍了查询优化预处理技术和子查询提升技术，接着详细讨论了存取路径的选择和路径代价的估算方法。

In query optimization module , the technique of query preprocessing and pulling subquery up is introduced , then the access path selection and the account method of const evaluation are discussed in detail .

具有强制存取控制的RBAC安全模型的设计与实现泛关系模型的目的在于获得完全的存取路径独立性。

Design and Implementation of RBAC Security Model of MAC The universal relation model aims at achieving the complete access path independence .