LOGLESS ATOMIC DATA MOVEMENT

• US 20170185642A1
• Filed: 03/13/2017
• Published: 06/29/2017
• Est. Priority Date: 04/30/2012
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP SE
• Inventors: Faerber, Franz, Lee, Juchang, Schreter, Ivan
• Granted Patent: US 10,853,351 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 16/162 Delete operations erasing in storage systems G06F3/0652
• CPC Class Codes: G06F 16/1744 using compression, e.g. sparse files
• CPC Class Codes: G06F 16/221 Column-oriented storage; Management thereof
• CPC Class Codes: G06F 16/2308 Concurrency control transaction processing G06F9/466
• CPC Class Codes: G06F 16/2365 Ensuring data consistency and integrity
• CPC Class Codes: G06F 16/2379 Updates performed during online database operations; commit processing
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/28 Databases characterised by their database models, e.g. relational or object models
• CPC Class Codes: G06F 3/0604 Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0638 Organizing or formatting or addressing of data
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/0683 Plurality of storage devices

Abstract

A system and method of logless atomic data movement. An internal transaction is started within a multi-level storage architecture, the internal transaction to merge data from the first level storage structure to the second level storage structure. Committed data is read from a first level storage structure of the multi-level storage architecture as specified by the internal transaction. The committed data from the first level storage structure is inserted into a second level storage structure in a bulk insertion process, and the committed data is marked as being deleted from the first level storage. The internal transaction is then committed to the multi-level storage architecture when the committed data has been inserted into the second level storage structure.

Claims

1. A computer-implemented method of log-less atomic data movement for use in a unified table database architecture of an in-memory computing system having a multi-level storage architecture, the multi-level storage architecture having a first level storage structure to store incoming data requests in a logical row format as data records and a second level storage structure to encode and store the data records in a logical column format, the method comprising:

starting, by the in-memory computing system, an internal transaction within the multi-level storage architecture, the internal transaction to merge data from the first level storage structure to the second level storage structure;

reading, by the in-memory computing system, committed data from the first level storage structure as specified by the internal transaction;

inserting, by the in-memory computing system, the committed data from the first level storage structure into the second level storage structure in a bulk insertion process;

marking, by the in-memory computing system, the committed data in the multi-level storage architecture as being deleted from the first level storage; and

committing, by the in-memory computing system, the internal transaction to the multi-level storage architecture when the committed data has been inserted into the second level storage structure.

2. The computer-implemented method in accordance with claim 1, wherein the bulk insertion process includes:

generating, by the in-memory computing system, a page identifier for the committed data; and

creating, by the in-memory computing system, an undo log for the page identifier.

3. The computer-implemented method in accordance with claim 1, further comprising marking the committed data as being deleted from the first level storage further includes adding a page delete version of the committed data to the first level storage in the multi-level storage architecture.

4. The computer-implemented method in accordance with claim 1, further comprising:

providing, by the in-memory computing system, a persistent storage layer configured to mimic the first level storage, the persistent storage layer comprising data structures containing value indices associated with data stored on the first level storage; and

,

removing, by the in-memory computing system, individual data from the persistent storage layer in response to an indication that individual data has been removed from the first level storage and saved to the second level storage of the multi-level storage architecture.

5. The computer-implemented method in accordance with claim 1, further comprising:

receiving, by the in-memory computing system, a request to merge new data with data stored in the second level storage structure;

determining, by the in-memory computing system, whether the dictionary associated with the new data is a subset of the dictionary associated with the data stored in the second level storage structure; and

,

generating, by the in-memory computing system, in response to determining that the dictionary associated with the new data is a subset of the dictionary associated with the data stored in the second level storage structure, a dictionary for the combined data based on the dictionary associated with the data stored in the second level storage structure.

6. The computer-implemented method in accordance with claim 1, further comprising:

determining, by the in-memory computing system, a sort pattern for the columns in the second level storage structure that would provide the highest level of compression for the data as a whole in the multi-level storage architecture;

sorting, by the in-memory computing system, the columns in the second level storage structure in accordance with the determined sort pattern.

7. A computer implemented method of log-less atomic data movement comprising:

providing a unified table database architecture of an in-memory computing system, the unified table architecture having a multi-level storage architecture, the multi-level storage architecture having a first level storage structure to store incoming data requests in a logical row format as data records and a second level storage structure to encode and store the data records in a logical column format;

starting, by the in-memory computing system, an internal transaction within the multi-level storage architecture, the internal transaction to merge data from the first level storage structure to the second level storage structure;

reading, by the in-memory computing system, committed data from the first level storage structure as specified by the internal transaction;

inserting, by the in-memory computing system, the committed data from the first level storage structure into the second level storage structure in a bulk insertion process;

marking, by the in-memory computing system, the committed data in the multi-level storage architecture as being deleted from the first level storage; and

committing, by the in-memory computing system, the internal transaction to the multi-level storage architecture when the committed data has been inserted into the second level storage structure.

8. The computer implemented method in accordance with claim 7, wherein the bulk insertion process includes:

generating, by the in-memory computing system, a page identifier for the committed data; and

creating, by the in-memory computing system, an undo log for the page identifier.

9. The computer implemented method in accordance with claim 7, further comprising marking the committed data in the multi-level storage architecture as being deleted from the first level storage further includes adding a page delete version of the committed data to the first level storage.

10. The computer implemented method in accordance with claim 7, wherein the starting, the reading, the inserting, the marking, and the committing are performed by one or more processors.

11. A system for log-less atomic data movement in a unified table database architecture comprising:

at least one programmable processor;

a multi-level storage architecture having a first level storage structure to store incoming data requests in a logical row format as data records and a second level storage structure to encode and store the data records in a logical column format; and

a non-transitory machine-readable medium storing instructions that, when executed by the at least one processor, cause the at least one programmable processor to perform operations comprising;

starting an internal transaction within the multi-level storage architecture, the internal transaction to merge data from the first level storage structure to the second level storage structure;

reading committed data from the first level storage structure as specified by the internal transaction;

inserting the committed data from the first level storage structure into the second level storage structure in a bulk insertion process;

marking the committed data in the multi-level storage architecture as being deleted from the first level storage; and

committing the internal transaction to the multi-level storage architecture when the committed data has been inserted into the second level storage structure.

12. The system in accordance with claim 11 wherein the bulk insertion process includes:

generating a page identifier for the committed data; and

creating an undo log for the page identifier.

13. The system in accordance with claim 11, wherein the operations further comprise marking the committed data as being deleted from the first level storage further includes adding a page delete version of the committed data to the first level storage in the multi-level storage architecture.

14. A computer-implemented method of log-less atomic data movement in a unified table database architecture, the computer-implemented method performed by an in-memory computer system, the method comprising:

merging, by the in-memory computing system, data from a first level storage structure to a second level storage structure of a multi-level storage database architecture, the first level storage structure configured to store incoming data requests in a logical row format and the second level storage structure configured to encode and store the data records in a logical column format;

differentiating, by the in-memory computing system, between committed data and non-committed data in the first level storage structure;

reading, by the in-memory computing system, the committed data from the first level storage structure as specified by the merge;

inserting, by the in-memory computing system, the committed data from the first level storage structure into the second level storage structure in a bulk insertion process;

marking, by the in-memory computing system, the committed data in the multi-level storage architecture as being deleted from the first level storage; and

committing, by the in-memory computing system, the merged data to the multi-level storage architecture when the committed data has been inserted into the second level storage structure.

15. The computer-implemented method in accordance with claim 14 wherein the bulk insertion process includes:

generating, by the in-memory computing system, a page identifier for the committed data; and

creating, by the in-memory computing system, an undo log for the page identifier.

16. The computer-implemented method in accordance with claim 14, wherein the operations further comprise marking the committed data as being deleted from the first level storage further includes adding a page delete version of the committed data to the first level storage.

17. The computer implemented method in accordance with claim 14, wherein the starting, the reading, the inserting, the marking, and the committing are performed by one or more processors.

18. The computer implemented method in accordance with claim 14, further comprising marking the committed data as being deleted from the first level storage further includes adding a page delete version of the committed data to the first level storage.

19. The computer implemented method in accordance with claim 14, further comprising:

providing, by the in-memory computing system, a persistent storage layer configured to mimic the first level storage, the persistent storage layer comprising data structures containing value indices associated with data stored on the first level storage; and

,

removing individual data from the persistent storage layer in response to an indication that individual data has been removed from the first level storage and saved to the second level storage.

20. The computer implemented method in accordance with claim 14, further comprising:

determining, by the in-memory computing system, a sort pattern for columns in the second level storage structure

that would provide the highest level of compression for the data as a whole;

sorting, by the in-memory computing system, the columns in the second level storage structure in accordance with the determined sort pattern.