Ghost table joins in remote systems

Patent metadata

Field	Value
Publication number	US-9710516-B2
Application number	US-201414277284-A
Country	US
Kind code	B2
Filing date	May 14, 2014
Priority date	May 14, 2014
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

A system includes reception of a client query including a JOIN between a local database table of a first computing system and a remote table of a second computing system, transmission of an instruction to the second computing system to define a new table in the second computing system, the new table associated with a storage handler for retrieving data of the local database table, generation of a remote query of the second computing system, the remote query including a second JOIN between the new table and the remote table, transmission of the remote query to the second computing system, and reception of results of the remote query from the second computing system.

First claim

What is claimed is:

1. A system comprising:
a first computing system comprising:
a first data storage device storing a local database table comprising a plurality of columns and defined by a first schema;
a first memory storing first processor-executable program code; and
a first processor to execute the first processor-executable program code in order to cause the first computing system to:
receive a client query including a JOIN between the local database table and a remote table of a second computing system;
transmit an instruction comprising (i) a create table statement and (ii) a select statement to the second computing system to define a new table in the second computing system based on the create table statement, the new table comprising the plurality of columns and defined by the first schema, wherein the new table is associated with a storage handler for retrieving data of the local database table and wherein the select statement is for retrieving data from the local database table;
generate a remote query of the second computing system, the remote query including a second JOIN between the new table and the remote table;
transmit the remote query to the second computing system; and
receive results of the remote query from the second computing system.

2. A system according to claim 1 , further comprising the second computing system, the second computing system comprising:
a second memory storing second processor-executable program code; and
a second processor to execute the second processor-executable program code in order to cause the second computing system to:
define the new table associated with the storage handler for retrieving data of the local database table;
execute the storage handler to retrieve data of the local table;
perform the second JOIN between the new table and the remote table;
select rowsets from the second JOIN based on the remote query; and
return the rowsets to the first computing system as the results of the remote query.

3. A system according to claim 2 , wherein transmission of the instruction to the second computing system to define the new table in the second computing system comprises:
generation of a query to retrieve data of the local database table; and
generation of the instruction,
wherein the instruction includes the query.

4. A system according to claim 3 , wherein the query includes a table properties parameter, and
wherein the table properties parameter includes the query.

5. A system according to claim 4 , wherein the table properties parameter includes an authorization token to authorize access of the data of the local database table.

6. A system according to claim 3 , wherein execution of the storage handler to retrieve data of the local table comprises:
transmitting the query to the first computing system.

7. A system according to claim 1 , wherein transmission of the instruction to the second computing system to define the new table in the second computing system comprises:
generation of a query to retrieve data of the local database table; and
generation of the instruction,
wherein the instruction includes the query.

8. A system according to claim 7 , wherein the query includes a table properties parameter, and
wherein the table properties parameter includes the query and an authorization token to authorize access of the data of the local database table.

9. A computer-implemented method, comprising:
receiving a client query including a JOIN between a local database table of a first computing system and a remote table of a second computing system, the local database table comprising a plurality of columns and defined by a first schema;
transmitting an instruction comprising (i) a create table statement and (ii) a select statement to the second computing system to define a new table in the second computing system based on the create table statement, the new table comprising the plurality of columns and defined by the first schema, wherein the new table is associated with a storage handler for retrieving data of the local database table and wherein the select statement is for retrieving data from the local database table;
generating a remote query of the second computing system, the remote query including a second JOIN between the new table and the remote table;
transmitting the remote query to the second computing system; and
receiving results of the remote query from the second computing system.

10. A computer-implemented method according to claim 9 , further comprising:
defining the new table in the second computing system, the new table associated with the storage handler for retrieving data of the local database table;
executing the storage handler in the second computing system to retrieve data of the local table;
performing the second JOIN between the new table and the remote table in the second computing system;
selecting rowsets from the second JOIN based on the remote query in the second computing system; and
returning the rowsets to the first computing system as the results of the remote query.

11. A computer-implemented method according to claim 10 , wherein transmitting the instruction to the second computing system to define the new table in the second computing system comprises:
generating a query to retrieve data of the local database table; and
generating the instruction,
wherein the instruction includes the query.

12. A computer-implemented method according to claim 11 , wherein the query includes a table properties parameter, and
wherein the table properties parameter includes the query.

13. A computer-implemented method according to claim 12 , wherein the table properties parameter includes an authorization token to authorize access of the data of the local database table.

14. A computer-implemented method according to claim 11 , wherein executing the storage handler to retrieve data of the local table comprises:
transmitting the query to the first computing system.

15. A computer-implemented method according to claim 9 , wherein transmitting the instruction to the second computing system to define the new table in the second computing system comprises:
generating a query to retrieve data of the local database table; and
generating the instruction,
wherein the instruction includes the query.

16. A computer-implemented method according to claim 15 , wherein the query includes a table properties parameter, and
wherein the table properties parameter includes the query and an authorization token to authorize access of the data of the local database table.

17. A non-transitory computer-readable medium storing program code, the program code executable by a first processor of a first computing system to cause the first computing system to:
receive a client query including a JOIN between a local database table of a first computing system and a remote table of a second computing system, the local database table comprising the plurality of columns and defined by a first schema;
transmit an instruction comprising (i) a create table statement and (ii) a select statement to the second computing system to define a new table in the second computing system based on the create table statement, the new table comprising the plurality of columns and defined by the first schema, wherein the new table is associated with a storage handler for retrieving data of the local database table and wherein the select statement is for retrieving data from the local database table;
generate a remote query of the second computing system, the remote query including a

Assignees

• P Shahul Hameed
• Quaye George
• Chowdhuri Sudipto
• Pendap Santosh
• Sap Se

Inventors

• P Shahul Hameed
• Quaye George
• Chowdhuri Sudipto
• Pendap Santosh

Classifications

• G06F16/2456 Primary

  Join operations · CPC title

• G06F16/24537

  of operators · CPC title

• G06F16/2282

  Tablespace storage structures; Management thereof · CPC title

• G06F16/951

  Indexing; Web crawling techniques · CPC title

• G06F16/284

  Relational databases · CPC title