Tracking intermediate changes in database data
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.
1. A method comprising:
storing data in a first micro-partition of a data structure, the stored data in the first micro-partition being associated with a first timestamp;
storing transaction data associated with a transaction;
storing a second micro-partition including one or more modifications performed to the stored data in the first micro-partition in response to the transaction generating the second micro-partition at a second timestamp;
storing modification data tracking the modifications performed to the stored data in the first and second micro-partitions between the first and second timestamps;
receiving a query associated with the data structure;
determining that the query involves data related to the transaction;
joining the modification data with the transaction data to generate joined data; and
executing the query using the joined data.
2. The method of claim 1 , further comprising:
calculating tuple changes between each of a series of sequential micro-partition pairs between the first and second timestamps.
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 , where the transaction data is stored in the second micro-partition as metadata, wherein the transaction data includes one or more of: an identity of an account that initiated the transaction, the second time stamp, a third timestamp when the transaction was requested, a fourth 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, wherein the metadata is stored in immutable storage.
7. The method of claim 1 , further comprising:
accessing a delta table, the delta table storing final changes in the second micro-partition at the second timestamp from the first micro-partition at the first timestamp,
wherein the delta table stores an initial value of a row at the first timestamp and a final value of the row after performance of multiple modifications to the row at the second timestamp,
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 timestamps, 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 data structure, the stored data in the first micro-partition being associated with a first timestamp;
storing transaction data associated with a transaction;
storing a second micro-partition including one or more modifications performed to the stored data in the first micro-partition in response to the transaction generating the second micro-partition at a second timestamp;
storing modification data tracking the modifications performed to the stored data in the first and second micro-partitions between the first and second timestamps;
receiving a query associated with the data structure;
determining that the query involves data related to the transaction;
joining the modification data with the transaction data to generate joined data; and
executing the query using the joined data.
9. The system of claim 8 , the operations further comprising:
calculating tuple changes between each of a series of sequential micro-partition pairs between the first and second timestamps.
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 , where the transaction data is stored in the second micro-partition as metadata, wherein the transaction data includes one or more of: an identity of an account that initiated the transaction, the second time stamp, a third timestamp when the transaction was requested, a fourth 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, wherein the metadata is stored in immutable storage.
14. The system of claim 8 , the operations further comprising:
accessing a delta table, the delta table storing final changes in the second micro-partition at the second timestamp from the first micro-partition at the first timestamp,
wherein the delta table stores an initial value of a row at the first timestamp and a final value of the row after performance of multiple modifications to the row at the second timestamp, 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 timestamps, 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 data structure, the stored data in the first micro-partition being associated with a first timestamp;
storing transaction data associated with a transaction;
storing a second micro-partition including one or more modifications performed to the stored data in the first micro-partition in response to the transaction generating the second micro-partition at a second timestamp;
storing modification data tracking the modifications performed to the stored data in the first and second micro-partitions between the first and second timestamps;
receiving a query associated with the data structure;
determining that the query involves data related to the transaction;
joining the modification data with the transaction data to generate joined data; and
executing the query using the joined data.
16. The non-transitory computer readable storage media of claim 15 , further comprising:
calculating tuple changes between each of a series of sequential micro-partition pairs between the first and second timestamps.
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 , where the transaction data is stored in the second micro-partition as metadata, wherein the transaction data includes one or more of: an identity of an account that initiated the transaction, the second time stamp, a third timestamp when the transaction was requested, a fourth 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, wherein the metadata is stored in immutable storage.