公开(公告)号：EP3401807A1

公开(公告)日：2018-11-14

申请号：EP18171431.2

申请日：2018-05-09

Applicant: SAP SE

Inventor： BENSBERG, Christian ,  BOEHM, Alexander ,  DRAGUSANU, Adrian ,  CHENG, Xun ,  SHERKAT, Reza ,  NICA, Anisoara ,  ANDREI, Mihnea

IPC: G06F17/30

CPC classification number: G06F17/30584 ,  G06F17/30002 ,  G06F17/30303 ,  G06F17/30339 ,  G06F17/3051

Abstract: Disclosed herein are system, method, and computer program product embodiments for determining a constraint data statistics object is consistent. An embodiment operates by receiving a query for a database table. The embodiment determines a constraint data statistic object associated with a partition of the database table. The embodiment determines the constraint data statistics object is consistent with a data state of the partition of the database table based on consistency metadata of the constraint data statistics object. The embodiment processes the query for the database table based on the determining the constraint data statistics object is consistent with the data state of the partition of the database table.

公开(公告)号：EP4092543A1

公开(公告)日：2022-11-23

申请号：EP21210632.2

申请日：2021-11-26

Applicant: SAP SE

Inventor： JOSHI, Yogi ,  POCOL, Sergiu ,  DEHAAN, David ,  FARRAR, Daniel ,  NICA, Anisoara

IPC: G06F16/2453 ,  G06F16/2455 ,  G06F16/22

Abstract: Systems, methods, and computer media are described for index-based join size estimation. For a join operation between two tables, a filter is applied to the first table, resulting in a filter output. The filter output is then sampled. For each sample, an index for a second table is accessed and counts of records in the second table that match the sample are retrieved. Using the sample size and the retrieved counts from the index of the second table, a data size for the join operation can be efficiently and accurately estimated. Statistical confidence in the estimate can also be assessed using variance-based calculations.