When the index name is not specified, optimizer picks the cheapest single XML index access plan.
如果未指定索引名,优化器将选用成本最低的XML 索引访问计划。
An index only scan is an index access that is not followed by a table access because the index itself contains all the requested data.
仅扫描索引是未包含表访问的索引访问,因为索引本身包含了所有被请求的数据。
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。
If you use a single page size for relational and XML data, or for data and indexes, a 32kb page size may be beneficial for XML data but somewhat detrimental for relational data and index access.
如果为关系数据和XML数据,或者为数据和索引使用单一的页宽,那么32kb的页宽对于XML数据而言可能有利,但是不利于关系数据和索引的访问。
If you use a single page size for relational and XML data, or for data and indexes, a 32kb page size may be beneficial for XML data but somewhat detrimental for relational data and index access.
如果为关系数据和XML数据,或者为数据和索引使用单一的页宽,那么32kb的页宽对于XML数据而言可能有利,但是不利于关系数据和索引的访问。
应用推荐