Distributed relational dictionaries

Patent metadata

Field	Value
Publication number	US-10810195-B2
Application number	US-201815861212-A
Country	US
Kind code	B2
Filing date	Jan 3, 2018
Priority date	Jan 3, 2018
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

Techniques related to distributed relational dictionaries are disclosed. In some embodiments, one or more non-transitory storage media store a sequence of instructions which, when executed by one or more computing devices, cause performance of a method. The method involves generating, by a query optimizer at a distributed database system (DDS), a query execution plan (QEP) for generating a code dictionary and a column of encoded database data. The QEP specifies a sequence of operations for generating the code dictionary. The code dictionary is a database table. The method further involves receiving, at the DDS, a column of unencoded database data from a data source that is external to the DDS. The DDS generates the code dictionary according to the QEP. Furthermore, based on joining the column of unencoded database data with the code dictionary, the DDS generates the column of encoded database data according to the QEP.

First claim

What is claimed is:

1. A method comprising:
generating, by a query optimizer at a distributed database system, a first query execution plan for generating a first code dictionary and a first column of encoded database data, said first query execution plan specifying a first sequence of operations for generating said first code dictionary, said first code dictionary being a database table;
receiving, at said distributed database system, a first column of unencoded database data from a data source external to said distributed database system;
generating, at said distributed database system, said first code dictionary according to said first query execution plan;
based on joining said first column of unencoded database data with said first code dictionary, generating, at said distributed database system, said first column of encoded database data according to said first query execution plan; and
wherein the method is performed by one or more computing devices.

2. The method of claim 1 , wherein said data source external to said distributed database system is a centralized database system.

3. The method of claim 1 , further comprising sending, to said data source external to said distributed database system, an indication that said first column of encoded database data has been generated according to said first query execution plan.

4. The method of claim 1 , further comprising, after generating said first column of encoded database data according to said first query execution plan, causing said first code dictionary to be defined by a database dictionary of said data source external to said distributed database system.

5. The method of claim 1 , further comprising, prior to generating said first query execution plan, making a cost-based decision to generate said first column of encoded database data at said distributed database system instead of at said data source external to said distributed database system.

6. The method of claim 5 , wherein said cost-based decision is based on at least one of a group comprising column characteristics, available memory on a particular node of said distributed database system, and cost of data transfer among nodes of said distributed database system.

7. The method of claim 1 , wherein said first sequence of operations comprises performing a de-duplication operation before performing a ranking operation.

8. The method of claim 1 , wherein said first sequence of operations comprises performing a ranking operation before performing a de-duplication operation.

9. The method of claim 1 , wherein said first sequence of operations comprises a partitioning operation for distributing unencoded database data across multiple cores of a node of said distributed database system.

10. The method of claim 1 , further comprising generating, by said query optimizer at said distributed database system, a second query execution plan for generating a second code dictionary and a second column of encoded database data, said second query execution plan specifying a second sequence of operations for generating said second code dictionary, said second sequence of operations being different from said first sequence of operations, said second code dictionary being a database table.

11. One or more non-transitory storage media storing a sequence of instructions which, when executed by one or more computing devices, cause:
generating, by a query optimizer at a distributed database system, a first query execution plan for generating a first code dictionary and a first column of encoded database data, said first query execution plan specifying a first sequence of operations for generating said first code dictionary, said first code dictionary being a database table;
receiving, at said distributed database system, a first column of unencoded database data from a data source external to said distributed database system;
generating, at said distributed database system, said first code dictionary according to said first query execution plan; and
based on joining said first column of unencoded database data with said first code dictionary, generating, at said distributed database system, said first column of encoded database data according to said first query execution plan.

12. The one or more non-transitory storage media of claim 11 , wherein said data source external to said distributed database system is a centralized database system.

13. The one or more non-transitory storage media of claim 11 , wherein said sequence of instructions further comprise instructions, which when executed by said one or more computing devices, cause sending, to said data source external to said distributed database system, an indication that said first column of encoded database data has been generated according to said first query execution plan.

14. The one or more non-transitory storage media of claim 11 , wherein said sequence of instructions further comprise instructions, which when executed by said one or more computing devices, cause, after generating said first column of encoded database data according to said first query execution plan, causing said first code dictionary to be defined by a database dictionary of said data source external to said distributed database system.

15. The one or more non-transitory storage media of claim 11 , wherein said sequence of instructions further comprise instructions, which when executed by said one or more computing devices, cause, prior to generating said first query execution plan, making a cost-based decision to generate said first column of encoded database data at said distributed database system instead of at said data source external to said distributed database system.

16. The one or more non-transitory storage media of claim 15 , wherein said cost-based decision is based on at least one of a group comprising column characteristics, available memory on a particular node of said distributed database system, and cost of data transfer among nodes of said distributed database system.

17. The one or more non-transitory storage media of claim 11 , wherein said first sequence of operations comprises performing a de-duplication operation before performing a ranking operation.

18. The one or more non-transitory storage media of claim 11 , wherein said first sequence of operations comprises performing a ranking operation before performing a de-duplication operation.

19. The one or more non-transitory storage media of claim 11 , wherein said first sequence of operations comprises a partitioning operation for distributing unencoded database data across multiple cores of a node of said distributed database system.

20. The one or more non-transitory storage media of claim 11 , wherein said sequence of instructions further comprise instructions which, when executed by said one or more computing devices, cause generating, by said query optimizer at said distributed database system, a second query execution plan for generating a second code dictionary and a second column of encoded database data, said second query execution plan specifying a second sequence of operations for generating said second code dictionary, said second sequence of operations being different from said first sequence of operations, said second code dictionary being a database table.

Assignees

• Oracle Int Corp

Inventors

• Kandukuri Anantha Kiran
• Sundara Seema
• Idicula Sam
• Fender Pit
• Kunal Nitin
• Petride Sabina
• Giannikis Georgios
• Agarwal Nipun

Classifications

• H04L67/1097 Primary

  for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS] · CPC title

• G06F16/2453 Primary

  Query optimisation · CPC title

• G06F16/2282

  Tablespace storage structures; Management thereof · CPC title

• G06F16/221

  Column-oriented storage; Management thereof · CPC title

• G06F40/242

  Dictionaries · CPC title