Tracking intermediate changes in database data

Patent metadata

Field	Value
Publication number	US-12026153-B2
Application number	US-202318179762-A
Country	US
Kind code	B2
Filing date	Mar 7, 2023
Priority date	Nov 6, 2018
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

Systems, methods, and devices for tracking a series of changes to database data are disclosed. A method includes executing a transaction to modify data in a micro-partition of a table of a database by generating a new micro-partition that embodies the transaction. The method includes associating transaction data with the new micro-partition, wherein the transaction data comprises a timestamp when the transaction was fully executed, and further includes associating modification data with the new micro-partition that comprises an indication of one or more rows of the table that were modified by the transaction. The method includes joining the transaction data with the modification data to generate joined data and querying the joined data to determine a listing of intermediate modifications made to the table between a first timestamp and a second timestamp.

First claim

What is claimed is:

1. A method comprising:
storing data in a first micro-partition of a table;
executing a transaction related to the stored data in the first micro-partition to generate transaction data;
performing a plurality of modifications to the stored data in the first micro-partition to generate a second micro-partition and remove the first micro-partition from the table for executing the transaction;
generating a delta table, the delta table storing final changes to the stored data in the second micro-partition from the first micro-partition;
generating modification data, the modification data tracking the modifications performed to the stored data between the second micro-partition and the first micro-partition; and
joining the modification data with the transaction data to generate joined data, the joined data indicating intermediate changes to the stored data between the second micro-partition and the first micro-partition.

2. The method of claim 1 , further comprising:
determining tuple changes between each of a series of sequential micro-partition pairs between the first and second micro-partitions.

3. The method of claim 1 , wherein multiple modifications to a row of a plurality of rows in the first micro-partition are performed and the joined data indicates at least one intermediate change to the row between initial and final values.

4. The method of claim 1 , wherein the transaction data includes one or more of: an identity of an account that initiated the transaction, a first timestamp when the transaction was requested, a second timestamp when execution of the transaction began, a listing of all rows that were modified by the transaction, and details of the modifications.

5. The method of claim 1 , wherein the modification data is stored in the second micro-partition as metadata, wherein the modification data includes a lineage of modifications made to the table.

6. The method of claim 1 , wherein the transaction data and the modification data are stored in the second micro-partition as metadata in immutable storage.

7. The method of claim 1 , further comprising:
wherein the delta table includes information indicating which rows have been modified, final values of rows that have been modified between the first and second micro-partitions, and an action type of the modification for each row modified.

8. A system comprising:
one or more processors of a machine; and
a memory storing instructions that, when executed by the one or more processors, cause the machine to perform operations comprising:
storing data in a first micro-partition of a table;
executing a transaction related to the stored data in the first micro-partition to generate transaction data;
performing a plurality of modifications to the stored data in the first micro-partition to generate a second micro-partition and remove the first micro-partition from the table for executing the transaction;
generating a delta table, the delta table storing final changes to the stored data in the second micro-partition from the first micro-partition;
generating modification data, the modification data tracking the modifications performed to the stored data between the second micro-partition and the first micro-partition; and
joining the modification data with the transaction data to generate joined data, the joined data indicating intermediate changes to the stored data between the second micro-partition and the first micro-partition.

9. The system of claim 8 , the operations further comprising:
determining tuple changes between each of a series of sequential micro-partition pairs between the first and second micro-partitions.

10. The system of claim 8 , wherein multiple modifications to a row of a plurality of rows in the first micro-partition are performed and the joined data indicates at least one intermediate change to the row between initial and final values.

11. The system of claim 8 , wherein the transaction data includes one or more of: an identity of an account that initiated the transaction, a first timestamp when the transaction was requested, a second timestamp when execution of the transaction began, a listing of all rows that were modified by the transaction, and details of the modifications.

12. The system of claim 8 , wherein the modification data is stored in the second micro-partition as metadata, wherein the modification data includes a lineage of modifications made to the table.

13. The system of claim 8 , wherein the transaction data and the modification data are stored in the second micro-partition as metadata in immutable storage.

14. The system of claim 8 , wherein the delta table includes information indicating which rows have been modified, final values of rows that have been modified between the first and second micro-partitions, and an action type of the modification for each row modified.

15. A non-transitory computer readable storage media storing instructions that, when executed by one or more processors, cause the one or more processors to:
storing data in a first micro-partition of a table;
executing a transaction related to the stored data in the first micro-partition to generate transaction data;
performing a plurality of modifications to the stored data in the first micro-partition to generate a second micro-partition and remove the first micro-partition from the table for executing the transaction;
generating a delta table, the delta table storing final changes to the stored data in the second micro-partition from the first micro-partition;
generating modification data, the modification data tracking the modifications performed to the stored data between the second micro-partition and the first micro-partition; and
joining the modification data with the transaction data to generate joined data, the joined data indicating intermediate changes to the stored data between the second micro-partition and the first micro-partition.

16. The non-transitory computer readable storage media of claim 15 , further comprising:
determining tuple changes between each of a series of sequential micro-partition pairs between the first and second micro-partitions.

17. The non-transitory computer readable storage media of claim 15 , wherein multiple modifications to a row of a plurality of rows in the first micro-partition are performed and the joined data indicates at least one intermediate change to the row between initial and final values.

18. The non-transitory computer readable storage media of claim 15 , wherein the transaction data includes one or more of: an identity of an account that initiated the transaction, a first timestamp when the transaction was requested, a second timestamp when execution of the transaction began, a listing of all rows that were modified by the transaction, and details of the modifications.

19. The non-transitory computer readable storage media of claim 15 , wherein the modification data is stored in the second micro-partition as metadata, wherein the modification data includes a lineage of modifications made to the table.

20. The non-transitory computer readable storage media of claim 15 , wherein the transaction data and the modification data are stored in the second micro-partition as metadata in immutable storage.

21. The non-transitory computer readable storage media of claim 15 , wherein the delta table includes information indicating which rows have been modified, final values of rows that have been modified between the first and second micro-part

Assignees

• Snowflake Inc

Inventors

• Grabs Torsten
• Cseri Istvan
• Dageville Benoit

Classifications

• G06F16/24554

  Unary operations; Data partitioning operations · CPC title

• G06F16/2456

  Join operations · CPC title

• G06F16/2282

  Tablespace storage structures; Management thereof · CPC title

• G06F16/2379 Primary

  Updates performed during online database operations; commit processing · CPC title

• G06F16/219 Primary

  Managing data history or versioning (querying versioned data G06F16/2474; querying temporal data G06F16/2477) · CPC title