predicate filter model 谓词过滤模型
Now that the view injects the filter predicate at the SQL level, DB2 can take advantage of the usual database techniques, that is index access.
现在,该视图在sql级注入过滤谓词,DB 2可以利用通常的数据库技术,即索引访问。
This approach requires the federated system to retrieve a superset of the data referenced by the predicate from the remote data source, and then filter it locally against the predicate.
这种方法要求联邦系统首先从远程数据源获取由谓词引用的数据的一个超集,然后通过谓词在本地对其进行过滤。
The estimate for QUALIFIED_ROWS is obtained by multiplying the table cardinality (560,273 records) by the predicate filter factor (0.0014%).
用表基数(560,273 条记录)与谓词过滤因子 (0.0014%) 相乘就获得了 QUALIFIED_ROWS 的估计值。
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