公开(公告)号：US09235621B2

公开(公告)日：2016-01-12

申请号：US13754770

申请日：2013-01-30

Applicant: Oracle International Corporation

Inventor： Jianhua Liang ,  Srikanth Bellamkonda

IPC: G06F7/00 ,  G06F17/30

CPC classification number: G06F17/30483 ,  G06F17/30445

Abstract: According to one aspect of the invention, for a database statement that specifies rollup operations, a data distribution key may be selected among a plurality of candidate keys. Numbers of distinct values of the candidate keys may be monitored with respect to a particular set of rows. Hash values may also be generated by column values in the candidate keys. The data distribution key may be determined based on results of monitoring the numbers of distinct values of the candidate keys as well as the frequencies of hash values computed based on column values of the candidate keys. Rollup operations may be shared between different stages of parallel executing processes and data may be distributed between the different stages of parallel executing processes based on the selected data distribution key.

Abstract translation: 根据本发明的一个方面，对于指定汇总操作的数据库语句，可以在多个候选键中选择数据分配密钥。 可以相对于一组特定的行来监视候选键的不同值的数量。 哈希值也可以由候选键中的列值生成。 可以基于监视候选键的不同值的数量的结果以及基于候选键的列值计算的散列值的频率来确定数据分配密钥。 可以在并行执行过程的不同阶段之间共享汇总操作，并且可以基于所选择的数据分配密钥在并行执行过程的不同阶段之间分配数据。

公开(公告)号：US20140214800A1

公开(公告)日：2014-07-31

申请号：US13754770

申请日：2013-01-30

Applicant: ORACLE INTERNATIONAL CORPORATION

Inventor： Jianhua Liang ,  Srikanth Bellamkonda

IPC: G06F17/30

CPC classification number: G06F17/30483 ,  G06F17/30445

Abstract: According to one aspect of the invention, for a database statement that specifies rollup operations, a data distribution key may be selected among a plurality of candidate keys. Numbers of distinct values of the candidate keys may be monitored with respect to a particular set of rows. Hash values may also be generated by column values in the candidate keys. The data distribution key may be determined based on results of monitoring the numbers of distinct values of the candidate keys as well as the frequencies of hash values computed based on column values of the candidate keys. Rollup operations may be shared between different stages of parallel executing processes and data may be distributed between the different stages of parallel executing processes based on the selected data distribution key.

Abstract translation: 根据本发明的一个方面，对于指定汇总操作的数据库语句，可以在多个候选键中选择数据分配密钥。 可以相对于一组特定的行来监视候选键的不同值的数量。 哈希值也可以由候选键中的列值生成。 可以基于监视候选键的不同值的数量的结果以及基于候选键的列值计算的散列值的频率来确定数据分配密钥。 可以在并行执行过程的不同阶段之间共享汇总操作，并且可以基于所选择的数据分配密钥在并行执行过程的不同阶段之间分配数据。