Conrad Tang

20200175016, Jun 4, 2020

Dec 19, 2018

16/225009

- Dayton OH, US
Sreyas Srimath Tirumala - Los Angeles CA, US
Nurjahan Begum - Bellevue WA, US
Chandana Prakash - Seattle WA, US
Mohammed Al-Kateb - Rolling Hills Estates CA, US
Conrad Kwok-Wai Tang - Torrance CA, US
Mohamed Yassin Eltabakh - Worcester MA, US
Kassem Awada - Torrance CA, US
Grace Kwan-On Au - Rancho Palos Verdes CA, US

Teradata US, Inc. - Dayton OH

G06F 16/2453
G06F 16/27

Multiple cost models (e.g., a sub-operations costing model and logical-operations costing model) can be used to make cost estimations of execution of database queries in one and each one of the multiple heterogeneous database systems. As a result, a “hybrid” cost estimating mode can be used whereby two or more cost models can be used in a single database system in to order maximize the advantages and minimize the disadvantages of each of the cost models, thereby striving to achieve an optimal balance. In addition, cost estimation can be switched between a hybrid cost estimating mode and a single cost estimating mode. The switch can, for example, be made as a part of tuning phase, as more information about actual costs of execution of database queries becomes more available, or as a result of changes to the database system and/or it operations, and so on. As a result, a flexible cost estimating mechanism can also be provided.