Double node join algorithm makes out th ree query projects . node dynamically chooses query project according to the query cost and network condition 基于代价的两点连接算法利用代价估计模型，制定出三种查询执行计划，节点根据代价和网络状况，动态地选择查询计划。
Although the behavior of the optimizer is influenced by optcompind and directives as we talked above , the optimizer generally chooses a query plan base on the follow guidelines 虽然如上面所谈论的，优化器的行为受optcompind和查询命令的影响，但优化器通常是基于下列指导方针来选择查询计划：
By the methods of grouping visit , of iterative and layered research , it was not only resolving the difficult for writing t - sql , but also combining easily , helping to the vivid and the accuracy of searching 通过节点分组访问、分层迭代查询的方法，不仅解决非一致性数据库约束条件难写的问题，而且容易组合选择查询条件，有助于提高查询的灵活性与准确性。
Because no table is created for a query that does not return rows , if you process an insert query followed by a select query , the table created for the select query is named " table " , because it is the first table created 如果某个查询不返回行，则不会为该查询创建表，因此，如果您先处理一个插入查询，然后再处理一个选择查询，这样由于为选择查询创建的表是第一个表，所以该表将被命名为“ table ” 。
Since no table is created for a query that does not return rows , if you were to process an insert query followed by a select query , the table created for the select query would be named " table " , because it is the first table created 如果某个查询不返回行，则不会为该查询创建表，因此，如果您先处理一个插入查询，然后再处理一个选择查询，那么由于为选择查询创建的表是第一个表，所以该表将被命名为“ table ” 。
So the professional components of arcobjects are selected in the paper to construct application system of gis which is henan population electric map system ( hpems ) , with functions of data management , searching , spatial analysis and tools , showing windows , making maps and so on , which denotes one direction to design the application system of gis with more advanced functions or to combine functions of gis with management information system ( mis ) , decisive supporting system ( dss ) , office automation ( oa ) and so on 因此本文选择了arcgis的专业组件以构造gis的应用系统一一河南省人口电子地图系统( hpems ) ，并基于该组件提供的完备的空间数据处理、分析功能，利用可视化开发工具，进行了河南省人口电子地图的开发实践。设计功能如下:数据处理、选择查询、分析工具、窗口显示、制图输出等功能。这代表了一种设计具有更高级功能的gis应用系统或把gis功能与管理信息系统( mis ) 、决策支持系统( dss ) 、办公自动化( oa )等系统集成的方向。
According to the function of system , this system takes overhead crane as an example , overhead crane class is abstracted to demonstrate corresponding object by adopting object - oriented method , design and computing program is to analyse , compute , query and select crane ' s component , database is established to store data of standard parts and components in common use of crane ' s design manual 根据系统所要实现的功能，该系统以桥式起重机为例，采用面向对象的思想抽象出桥式起重机类来表述桥式起重机对象，通过桥式起重机的设计计算程序对起重机各机构进行计算分析和选择查询，数据库部分存储了起重机设计手册中一些常用标准零部件的各种数据。
