公开(公告)号：US20150363466A1

公开(公告)日：2015-12-17

申请号：US14301627

申请日：2014-06-11

申请人： International Business Machines Corporation

发明人： Andrey Balmin ,  Vuk Ercegovac ,  Jesse E. Jackson ,  Konstantinos Karanasos ,  Marcel Kutsch ,  Fatma Ozcan ,  Chunyang Xia

IPC分类号： G06F17/30

CPC分类号： G06F17/30466 ,  G06F17/30451 ,  G06F17/30469

摘要： In one embodiment, a computer-implemented method includes selecting one or more sub-expressions of a query during compile time. One or more pilot runs are performed by one or more computer processors. The one or more pilot runs include a pilot run associated with each of one or more of the selected sub-expressions, and each pilot run includes at least partial execution of the associated selected sub-expression. The pilot runs are performed during execution time. Statistics are collected on the one or more pilot runs during performance of the one or more pilot runs. The query is optimized based at least in part on the statistics collected during the one or more pilot runs, where the optimization includes basing cardinality and cost estimates on the statistics collected during the pilot runs.

摘要翻译： 在一个实施例中，计算机实现的方法包括在编译期间选择查询的一个或多个子表达。 一个或多个导频运行由一个或多个计算机处理器执行。 一个或多个导频运行包括与所选择的一个或多个子表达中的每一个相关联的导频运行，并且每个导频运行包括相关联的所选子表达式的至少部分执行。 飞行员运行在执行时执行。 在一次或多次飞行员运行期间，在一次或多次飞行员运行中收集统计数据。 该查询至少部分地基于在一个或多个试运行期间收集的统计数据进行优化，其中优化包括基于试点运行期间收集的统计数据的基数和成本估算。

公开(公告)号：US09836506B2

公开(公告)日：2017-12-05

申请号：US14301627

申请日：2014-06-11

申请人： International Business Machines Corporation

发明人： Andrey Balmin ,  Vuk Ercegovac ,  Jesse E. Jackson ,  Konstantinos Karanasos ,  Marcel Kutsch ,  Fatma Ozcan ,  Chunyang Xia

IPC分类号： G06F17/30

CPC分类号： G06F17/30466 ,  G06F17/30451 ,  G06F17/30469

摘要： In one embodiment, a computer-implemented method includes selecting one or more sub-expressions of a query during compile time. One or more pilot runs are performed by one or more computer processors. The one or more pilot runs include a pilot run associated with each of one or more of the selected sub-expressions, and each pilot run includes at least partial execution of the associated selected sub-expression. The pilot runs are performed during execution time. Statistics are collected on the one or more pilot runs during performance of the one or more pilot runs. The query is optimized based at least in part on the statistics collected during the one or more pilot runs, where the optimization includes basing cardinality and cost estimates on the statistics collected during the pilot runs.