The optimizer will choose nested-loop joins if.
如果满足下列条件,优化器将选择嵌套循环连接。
By default, the optimizer considers this type of scan.
默认情况下,优化器考虑这种类型的扫描。
The optimizer will use indexes in the following cases.
在下列情况下,优化器将使用索引。
The optimizer has many types of strategies for optimizing SQL.
优化器有许多类型的优化SQL的策略。
The following explains why the optimizer would add a SORT node.
以下解释了为什么优化器将添加SORT节点。
The optimizer will add more indexes to the IXAND based on cost.
优化器将根据成本向IXAND添加更多索引。
The total number of rows, estimated by the optimizer, is 2.176.
优化器估计的总行数是 2.176。
The optimizer USES all applicable XML indexes in the XANDOR plan.
优化器在XAND OR计划中使用所有合适的xml索引。
The sort heap size is used by the optimizer in determining access paths.
优化器用排序堆大小来确定存取路径。
For example, the optimizer must determine whether indexes should be used.
例如,优化器必须确定是否应使用索引。
A value of -1 means that the optimizer determines the degree of asynchrony.
若该选项值为- 1,则意味着优化器自行决定异步程度。
The optimizer performs complex calculations based on a host of information.
优化器根据许多信息执行复杂的计算。
The optimizer will decide whether an index can be used to evaluate a filter.
优化器将决定是否可以使用索引来评估筛选器。
The optimizer may add more indexes to the IXAND plan in a cost-based fashion.
优化器可能会以一种基于成本的方式将更多索引加入到 IXAND计划中。
The optimizer chooses between the two access methods using a cost-based analysis.
优化器将通过基于成本的分析来在这两个访问方法之间进行选择。
The estimated costs are cost units that the optimizer uses to compare query plans.
估算成本是优化器用来比较查询计划的成本单元。
The optimizer picks additional indexes for the IXAND plan in a cost-based fashion.
优化器将以一种基于成本的方式为IXAND计划挑选额外的索引。
The important information used by the optimizer for a tablespace is the following.
下面是优化器为表空间所使用的重要信息。
The optimizer will compare the cost of each method to determine the best one to use.
优化器将比较每种方法的成本,确定使用最好的一种。
The optimizer will choose dynamic hash join if none of the joined columns has index.
如果连接列上不存在索引,那么优化器将选择动态哈希连接。
Note: Here is a query for which the optimizer cannot consider using the functional index.
注意:优化器不会对下面这个查询使用函数索引。
The value ANY allows the optimizer to determine the number of ATQs for a given query plan.
值ANY允许优化器决定一个给定查询计划的 ATQ的数量。
The inconsistent statistics may also mislead the optimizer into choosing a bad access path.
不一致的统计数据还会误导优化器选择糟糕的访问路径。
You can use the following command to tell the optimizer to not use any optimization profile.
可以使用以下命令告诉优化器不要使用任何优化配置文件。
Therefore, in Figure 7 the optimizer chooses to sort the composite for the nested loop join.
因此,在图7中优化器选择排序嵌套循环联接的复合物。
The optimizer can use data distributions to calculate selectivity for the filters in a query.
优化器可以使用数据分布来计算查询中过滤器的选择率。
Goal directives that force the optimizer to use the designated rules to return query results.
目标指示,强制优化器使用指定的规则来返回查询结果。
The optimizer bases query cost estimates on the number of rows to be retrieved from each table.
优化器将根据在每个表中检索的行数来评估查询成本。
For example, what if the two local predicates are not as selective as estimated by the optimizer?
例如,如果这两个本地谓词选择性没有优化器评估的强,怎么办?
Analyze the query access plan to visualize the choices the optimizer makes in accessing the data.
分析查询访问计划,从而可以切实看到优化器对访问数据作出的选择。
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