Methods, systems, and products for maintaining data consistency in a stream warehouse

1. A method, comprising:

continuously receiving, by a server, a stream of data to a data warehouse;

retrieving, by the server, a partitioning function to apply to the stream of data;

partitioning, by the server, the stream of data into a plurality of temporal partitions according to the partitioning function, with each one of the plurality of temporal partitions containing a portion of the stream of data within a contiguous range of time and identified by an integer value;

assigning, by the server, an open consistency to a single partition of the plurality of temporal partitions in response to determining at least one data record is contained within the single partition;

assigning, by the server, a closed consistency to the single partition in response to determining no more data records are expected within the single partition;

assigning, by the server, a complete consistency to the single partition in response to determining all expected data records have arrived within the single partition;

assigning, by the server, a query consistency to the single partition based on at least one of the open consistency, the closed consistency, and the complete consistency;

receiving, by the server, a query; and

determining, by the server, an answer associated with the query based on the query consistency.

2. The method according to claim 1 , further comprising answering the query.

3. The method according to claim 1 , further comprising inferring the query consistency.

4. The method according to claim 1 , further comprising determining the query consistency from a source partition in the plurality of temporal partitions.

5. The method according to claim 1 , further comprising determining the query consistency from a set of source partitions in the plurality of temporal partitions.

6. The method according to claim 1 , further comprising refreshing the plurality of temporal partitions according to an update consistency.

7. The method according to claim 1 , further comprising:

deriving a directed acyclic graph; and

performing a reverse breadth-first search of the directed acyclic graph.

8. The method according to claim 1 , further comprising marking a dependent table with a marker.

9. A system, comprising:

a processor; and

a memory storing code that when executed causes the processor to perform operations, the operations comprising:

continuously receiving a stream of data to a data warehouse;

deriving a source table from the data contained within the stream of data;

retrieving a partitioning function to apply to the stream of data;

partitioning, by the server, the stream of data into a plurality of temporal partitions according to the partitioning function, with each one of the plurality of temporal partitions containing a portion of the stream of data within a contiguous range of time and identified by an integer value;

storing the plurality of temporal partitions as warehouse data tables;

when at least one data record is contained within a single partition of the plurality of temporal partitions, then assigning an open consistency to the single partition;

when no more data records are expected within the single partition, then assigning a closed consistency to the single partition;

when all expected data records have arrived within the single partition, then assigning a complete consistency to the single partition;

assigning a query consistency to the single partition based on at least one of the open consistency, the closed consistency, and the complete consistency;

receiving the query; and

answering the query with the query consistency.

10. The system according to claim 9 , wherein the operations further comprise retrieving an inference rule associated with the open consistency.

11. The system according to claim 9 , wherein the operations further comprise retrieving an inference rule associated with the closed consistency.

12. The system according to claim 9 , wherein the operations further comprise retrieving an inference rule associated with the closed consistency.

13. The system according to claim 9 , wherein the operations further comprise assigning the open consistency when the single partition contains no data records.

14. The system according to claim 9 , wherein the operations further comprise comparing source metadata in a source partition to destination metadata in a destination partition.