Non-materialized tables with standing queries

• US 10,642,844 B2
• Filed: 03/30/2017
• Issued: 05/05/2020
• Est. Priority Date: 04/01/2016
• Status: Active Grant

• Current Assignee: Arista Networks, Inc.
• Original Assignee: Arista Networks, Inc.
• Inventors: Greenwald, Michael, Schleimer, Stephen
• Primary Examiner(s): Pham, Tuan A
• Application Number:
  US15/473,932
• Publication Number:
  US 20170286500A1
• Time in Patent Office: 1,132 Days
• Field of Search: None
• CPC Class Codes: G06F 16/24568 Data stream processing; Continuous queries

Abstract

A network device includes a database that includes a materialized table and a non-materialized table. The network device also includes a standing query instance that generates an output that is stored in the non-materialized table. The database obtains a request that specifies the output, and provides the output in response to the request.

Claims

1. A network device, comprising:

a database comprising;

a materialized table comprising a value;

a non-materialized table comprising an output; and

a query instance programmed to generate the output that is stored in the non-materialized table using the value,

wherein the database is programmed to;

delete the output from the non-materialized table after it has been read by a consumer,

after the deletion, obtain a request for the output,

determine, in response to the request, that the output is not present in the non-materialized table,

in response to the determining, initiating regeneration of the output using at least the value in the materialized table to obtain a regenerated output, and

provide the regenerated output in response to the request.

2. The network device of claim 1, wherein regenerating the output comprises sending a request to the query instance to regenerate the output.

3. The network device of claim 2, wherein the request specifies an entry of the materialized table.

4. The network device of claim 3, wherein the request further specifies an entry of a second non-materialized table.

5. The network device of claim 1, wherein providing the regenerated output comprises storing the regenerated output in the non-materialized table.

6. The network device of claim 1, wherein the network device is one selected from a group consisting of a router, a switch, and a multilevel switch.

7. A method of operating a network device, comprising:

deleting an output from a non-materialized table in a database in the network switch after it has been read by a consumer;

after the deleting, obtaining a request for the output; and

in response to the request;

determining that the output is not present in the non-materialized table,

in response to the determining, initiating regeneration of the output using at least a value in a materialized table in the database to obtain a regenerated output; and

providing the regenerated output in response to the request.

8. The method of claim 7, wherein regenerating the output comprises sending a request to a query instance that generated the output to regenerate the output, wherein the query instance is executing on the network device.

9. The method of claim 8, wherein the request specifies an entry of the materialized table, wherein the entry comprises at least the value.

10. The method of claim 9, wherein the request further specifies an entry of a second non-materialized table in the database.

11. The method of claim 7, wherein providing the regenerated output comprises storing the regenerated output in the non-materialized table.

12. The method of claim 11, wherein providing the regenerated output further comprises propagating the regenerated output by an observer executing on the network device.

13. The method of claim 7, wherein the regenerated output is stored in the non-materialized table by a modifier executing on the network device.

14. A non-transitory computer readable medium (CRM) storing instructions, the instructions when executed by a network device cause the network device to:

deleting an output from a non-materialized table in a database in a network device after it has been read by a consumer;

after the deleting, obtain a request for the output; and

in response to the request;

determining that the output is not present in the non-materialized table,

in response to the determining, initiating regeneration of the output using at least a value in a materialized table in the database to obtain a regenerated output; and

providing the regenerated output in response to the request.

15. The non-transitory CRM of claim 14, wherein regenerating the output comprises sending a request to a query instance that generated the output to regenerate the output.

16. The non-transitory CRM of claim 15, wherein the request specifies an entry of the materialized table, wherein the entry comprises at least the value.

17. The non-transitory CRM of claim 16, wherein the request further specifies an entry of a second non-materialized table in the database.