帮忙解释这个提示

knife800

免费乐捐，感谢支持

This query requires 4 auxiliary scan descriptors, but currently there are only 0 auxiliary scan descriptors available. Either raise the value of the 'number of auxiliary scan descriptors' configuration parameter or try your query later.

如何修改?

flybean

If your queries need more scan descriptors, use one of the following methods to remedy the problem:

• Rewrite the query, or break it into steps using temporary tables. For data-only-locked tables, consider adding indexes if there are many table scans.

• Redesign the table’s schema so that it uses fewer scan descriptors, if it uses a large number of referential integrity constraints. You can find how many scan descriptors a query would use by enabling set showplan, noexec on before running the query.

• Increase the number of aux scan descriptors setting.

每个连接和工作进程需要独占的48个扫描描述符(用户表：16，工作表：12，系统表：20)。如果一个查询使用了超过独占的扫描描述符的个数(不是总数，是三项中任意一项超过)，则会从number of auxiliary scan descriptors中申请。

建议你首先检查一下SQL，是否需要这么多描述符？