一个参数标记或一个主变量。

A parameter marker or host variable.

youdao

您还研究了参数标记/主变量的使用会为 DB2 优化器对分布统计信息的考虑带来怎样的限制。

You have also examined how the use of parameter markers/host variables may limit the consideration of distribution statistics by the DB2 optimizer.

youdao

对全部输人特征参数进行了主变量分析，给出了采用不同数量特征参数的优化组合方案。

The optimum combinations adopting different numbers of characteristic parameters have been obtained by analyzing the main variables of all the input parameters.

youdao