ESTIMATION OF QUERY INPUT/OUTPUT (I/O) COST IN DATABASE

• US 20150149418A1
• Filed: 06/10/2014
• Published: 05/28/2015
• Est. Priority Date: 11/27/2013
• Status: Active Grant

• Current Assignee: Sybase Incorporated (SAP SE)
• Original Assignee: Ivan Bowman, Pedram Ghodsnia
• Inventors: Ghodsnia, Pedram, Bowman, Ivan
• Granted Patent: US 9,594,781 B2
• Time in Patent Office: Days
• US Class Current: 707/688
• CPC Class Codes: G06F 16/217 Database tuning G06F16/2282 takes precedence; database performance monitoring G06F11/3409

Abstract

Disclosed herein are system, method, and computer program product embodiments for calibrating and using a stable storage model. An embodiment operates by generating, by a central computer, an access request for a stable storage, wherein the access request comprises a plurality of page accesses; measuring a cost to execute the access request on the stable storage; amortizing the cost over the plurality of page accesses; and calibrating, by the central computer, a stable storage model based on the amortized cost.

Claims

1. A method comprising:

generating, by a central computer, an access request comprising a plurality of page accesses for a stable storage;

measuring a cost to execute the access request on the stable storage;

amortizing the cost over the plurality of page accesses; and

calibrating, by the central computer, a stable storage model based on the amortized cost.

2. The method of claim 1, wherein the access request includes a request for a plurality of queue depths.

3. The method of claim 1, wherein the access request includes a request for a plurality of band sizes.

4. The method of claim 1, wherein the access request includes a plurality of requests to fully calibrate the stable storage.

5. The method of claim 1, wherein calibrating the stable storage model further comprises using interpolation to estimate the access cost for a queue depth/band size combination not included in the access request.

6. The method of claim 1, wherein calibrating the stable storage model further comprises using bilinear interpolation to estimate the access cost for a queue depth/band size combination not included in the access request.

7. The method of claim 1, wherein calibrating the stable storage model comprises selecting a default stable storage model from a plurality of default stable storage models.

8. The method of claim 7, wherein the plurality of default stable storage models includes a model for a solid state device (SSD) and a model for a hard disk drive (HDD).

9. The method of claim 1, further comprising determining if the amortized cost improved by comparing the amortized cost to a previously calculated amortized cost.

10. The method of claim 9, further comprising generating an additional access request if a threshold is met when comparing the amortized cost to the previously calculated amortized cost.

11. A computer-readable device having instructions stored thereon, execution of which, by a computing device, causes the computing device to perform operations comprising:

receiving a queue depth and a band size associated with an access request; and

determining an estimated access cost for the access request based on the queue depth and band size.

12. The computer-readable device of claim 11, wherein the determining comprises identifying the estimated access cost in a table.

13. The computer-readable device of claim 11, wherein the determining comprises interpolating calibrated estimate access costs to determine the estimated access cost.

14. The computer-readable device of claim 13, wherein the interpolation is bilinear interpolation.

15. The computer-readable device of claim 11, wherein the access request comprises a plurality of access requests and wherein the queue depth and band size are selected from the queue depth and band sizes of the plurality of access requests respectfully.

16. A system comprising:

a stable storage configured to store a database file;

an optimization module, in communication with the stable storage, configured to determine an amortized cost of an access request made to the database file, wherein the access request has a given band size and queue depth; and

an access module, in communication with the optimization module and the stable storage, configured to submit Input/Output (I/O) requests to the database file based on the amortized cost.

17. The system of claim 16, wherein the access module is configured to maintain a plurality of execution plans indicating how I/O requests are to be submitted to the database file.

18. The system of claim 17, wherein the access module is further configured to select an execution plan based on the amortized cost.

19. The system of claim 16, wherein the access model is configured to access a plurality of default stable storage models.

20. The system of claim 19, wherein the access model is further configured to select a stable storage model from the plurality of default stable storage modes based on the amortized cost and to select an execution plan based on the selected stable storage model.