Integrating tablespaces with different block sizes

• US 20020143733A1
• Filed: 05/30/2001
• Published: 10/03/2002
• Est. Priority Date: 05/30/1997
• Status: Active Grant

• Current Assignee: Oracle International Corporation (Oracle Corporation)
• Original Assignee: Oracle International Corporation (Oracle Corporation)
• Inventors: Loaiza, Juan R., Lahiri, Tirthankar, Pareek, Alok, Mukkamalla, Sreedhar, Nithrakashyap, Arvind, Lee, J. William, Ngai, Gary C.
• Granted Patent: US 7,031,987 B2
• Time in Patent Office: Days
• US Class Current: 707/1
• CPC Class Codes: G06F 16/00 Information retrieval; Database structures therefor; File system structures therefor
• CPC Class Codes: G06F 16/283 Multi-dimensional databases or data warehouses, e.g. MOLAP or ROLAP
• CPC Class Codes: G06F 16/9017 using directory or table look-up use of a directory or look-up table in file systems G06F16/13
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

Provided herein is a mechanism that allows a given database system to access data blocks from another database system, where data blocks from the given database system and data blocks from the other database system have different sizes. According to an aspect of the present invention, a tablespace in the other database system contained the data blocks. The tablespace is detached from the other database system and integrated into the given database, which is capable of processing data stored in data blocks of a different sizes.

Claims

1. A method for database systems to access data from other database systems, the method comprising the steps of:

a first database system directly storing first data in first data blocks having a first data block size;

said first database system directly accessing a copy of second data blocks in which a second database system directly stored second data; and

said second data blocks having at least one data block with a second data block size different than said first data block size.

2. The method of claim 1, wherein the method further includes the step of integrating said copy of said second data blocks within said first database system as a tablespace that includes said copy of said second data blocks

3. The method of claim 1, wherein the step of accessing a copy of second data blocks includes storing user data in said copy of said second data blocks.

4. The method of claim 1, wherein the method further includes the step of detaching one or more tablespaces from said second database system, wherein said one or more tablespaces include said second data blocks.

5. The method of claim 1, wherein each data block of said copy of said second data blocks has said second data block size.

6. The method of claim 1, further including the step of generating metadata that specifies a plurality of block sizes for data blocks directly accessible to said first database system.

7. The method of claim 6, wherein:

said metadata defines tablespaces and specifies for each tablespace of said tablespaces a particular data block size for all data blocks in said tablespace; and

the method further includes the step of integrating said copy of said second data blocks within said first database system as at least one tablespace that includes said copy of said second data blocks, and

wherein the step of integrating includes modifying said metadata to reflect said second data block size for said at least one tablespace.

8. The method of claim 1, wherein said first database system is a data warehouse and said second database system is a source database system for said data warehouse.

9. The method of claim 8, further including the step of integrating said copy of said second data blocks within said data warehouse as a tablespace that includes said copy of said second data blocks.

10. The method of claim 1,

wherein first data files contain said first data blocks and second data files contain said second data blocks;

and

wherein the method further includes the step of generating a mapping;

between said first data files and said first data block size, and

between said second data files and said second data block size.

11. The method of claim 1, wherein a first tablespace contains said first data blocks and a second tablespace contains said second data blocks;

and

wherein the method further includes the step of generating a mapping;

between said first tablespace and said first data block size, and

between said second tablespace and said second data block size.

12. The method of claim 1,

wherein said first database system includes a buffer cache in which said first database system stores data blocks of multiple sizes;

and

wherein said method further includes the step of storing said first data blocks and said second data blocks in said buffer cache.

14. The computer-readable medium of claim 13, wherein the computer-readable medium further includes instructions for performing the step of integrating said copy of said second data blocks within said first database system as a tablespace that includes said copy of said second data blocks.

15. The computer-readable medium of claim 13, wherein the step of accessing a copy of second data blocks includes storing user data in said copy of said second data blocks.

16. The computer-readable medium of claim 13, wherein the computer-readable medium further includes instructions for performing the step of detaching one or more tablespaces from said second database system, wherein said one or more tablespaces include said second data blocks.

17. The computer-readable medium of claim 13, wherein each data block of said copy of said second data blocks has said second data block size.

18. The computer-readable medium of claim 13, further including instructions for performing the step of generating metadata that specifies a plurality of block sizes for data blocks directly accessible to said first database system.

19. The computer-readable medium of claim 18, wherein:

said metadata defines tablespaces and specifies for each tablespace of said tablespaces a particular data block size for all data blocks in said tablespace; and

the computer-readable medium further includes instructions for performing the step of integrating said copy of said second data blocks within said first database system as at least one tablespace that includes said copy of said second data blocks, and

wherein the step of integrating includes modifying said metadata to reflect said second data block size for said at least one tablespace.

20. The computer-readable medium of claim 13, wherein said first database system is a data warehouse and said second database system is a source database system for said data warehouse.

21. The computer-readable medium of claim 20, further including instructions for performing the step of integrating said copy of said second data blocks within said data warehouse as a tablespace that includes said copy of said second data blocks.

22. The computer-readable medium of claim 13,

wherein first data files contain said first data blocks and second data files contain said second data blocks;

and

wherein the computer-readable medium further includes instructions for performing the step of generating a mapping;

between said first data files and said first data block size, and

between said second data files and said second data block size.

23. The computer-readable medium of claim 13,

wherein a first tablespace contains said first data blocks and a second tablespace contains said second data blocks;

and

wherein the computer-readable medium further includes instructions for performing the step of generating a mapping;

between said first tablespace and said first data block size, and

between said second tablespace and said second data block size.

24. The computer-readable medium of claim 13,

wherein said first database system includes a buffer cache in which said first database system stores data blocks of multiple sizes;

and

wherein said computer-readable medium further includes the step of storing said first data blocks and said second data blocks in said buffer cache.

13. A computer-readable medium carrying one or more sequences of instructions for database systems to access data from other database systems, wherein execution of the one or more sequences of instructions by one or more processors causes the one or more processors to perform the steps of:

a first database system directly storing first data in first data blocks having a first data block size;

said first database system directly accessing a copy of second data blocks in which a second database system directly stored second data; and

said second data blocks having at least one data block with a second data block size different than said first data block size.