由于DB 2优化器在准备阶段不知道参数标记的值，因此生成了一个在所有情况下都不是最优的万能(one - size - fits - all)访问计划。

Because the DB2 optimizer does not know the values of the parameter markers in the prepare phase, a one-size-fits-all access plan is generated that cannot be optimal in all cases.

youdao

为特定类型的复杂数据调整万能服务器的查询优化器，能大大提高这些数据类型的查询速度。

Tuning the Universal Server's query optimizer for particular types of complex data can vastly improve querying speed on those data types.

youdao

当然，所有技术都不是万能的，在实践中应该不断调整和优化。

Of course, no technique is universal, so we should reorganize and optimize it in practice.

youdao