This is the same join predicate applied at FILTER(10).
和应用于FILTER(10) 的连接断言相同。
Query 2 applies the join predicate to the authors table.
查询2对authors表应用连接谓词。
The LIKE predicate can therefore be used as a fuzzy join predicate.
因此,可以使用like谓词作为模糊联结谓词。
In both queries, the join predicate is expressed within the square brackets.
在这两个查询中,方括号中表示了连接谓词。
The following query explicitly casts both sides of the join predicate to DOUBLE.
以下查询明确地将连接谓词的两端转换为DOUBLE。
That is, table CUST_INTEREST could be very selective through the join predicate.
即,通过连接谓词,CUST_INTEREST表的选择性非常强。
When you use the partitioning key in the join predicate, a final consideration needs to be mentioned.
如果在连接谓词中使用分区键(partitioning key),最后还有一点考虑需要顾及。
Generate the expression for the join predicate by applying the join operator to the expressions for the left and right attributes.
将联结操作符应用于左右属性的表达式,从而产生联结谓词的表达式。
Note that the join predicate on the author ID does not contain a literal value that would indicate the data type of the comparison.
请注意,authorID上的连接谓词没有包含文字值,该文字值将表明比较的数据类型。
As a slightly more sophisticated example, here is a query involving a spatial join, that is, a join where the join predicate is a spatial function.
作为一个稍微复杂些的示例,下面给出一个涉及空间联结(即其中的联结谓词是空间函数的联结)的查询。
TBSCAN (4) — Since this is the same join predicate being resolved at NLJOIN (2), and there are no additional local predicates, we can ignore this operator.
TBSCAN(4)——因为这个连接断言和NLJOIN(2)分析出的相同,并且没有其他局部断言,可以忽略该操作。
When an in predicate (or an equivalent or predicate) is used, the optimizer considers an IN-to-JOIN transformation, converting the in predicate to a join predicate.
当使用了一个in谓词(或一个等价的or谓词)时,优化器将会考虑使用一个in到join的变换,将一个in谓词转换成一个连接谓词。
For example, this might happen when two ore more of the tables in the MQT have a referential integrity relationship defined and the join predicate is on their primary key - foreign key columns.
例如,当MQT中的两个或多个表定义了引用完整性关系并且联结谓词在它们自己的主键-外键列上时,就会出现这种情况。
For example, this might happen when two ore more of the tables in the MQT have a referential integrity relationship defined and the join predicate is on their primary key - foreign key columns.
例如,当MQT中的两个或多个表定义了引用完整性关系并且联结谓词在它们自己的主键-外键列上时,就会出现这种情况。
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