Data processing with nullable schema information

1. A computer-implemented method executed on a processor for improving performance of data processing with nullable schema information by using a data processing framework, the method comprising:

reading, by the processor, data from one or more blocks forming a column, where the data is stored in a database including the one or more blocks;

determining, by the processor, whether any row in each block of the one or more blocks includes null data;

generating and executing, by the data processing framework, optimized code for each block of the one or more blocks that is detected to be free of null data; and

generating and executing, by the data processing framework, non-optimized code for each block of the one or more blocks that is detected to include null data such that an original format of the one or more blocks detected to include the null data is maintained;

creating metadata for each block of the one or more blocks when an in-memory structure is created; and

employing the determining step when a schema is updated.

2. The method of claim 1 , wherein the data processing framework is a cluster computing engine.

3. The method of claim 1 , further comprising creating metadata for each block of the one or more blocks when a file is created.

4. The method of claim 1 , further comprising, when executing a subquery, employing the determining step to an output of the subquery.

5. The method of claim 1 , further comprising employing the determining step when an index is created.

6. The method of claim 1 , further comprising employing the determining step when a query is executed, the query scanning a part of a column or a whole column.

7. The method of claim 1 , further comprising forming the column in a data frame including a plurality of rows and a plurality of columns.

8. The method of claim 1 , further comprising storing and reusing results of the determining step.

9. A computer system for improving performance of data processing with nullable schema information by using a data processing framework, the computer system comprising:

a memory; and

at least one processor in communication with the memory, wherein the computer system is configured to:

read, by the processor, data from one or more blocks forming a column, where the data is stored in a database including the one or more blocks;

determine, by the processor, whether any row in each block of the one or more blocks includes null data;

generate and execute, by the data processing framework, optimized code for each block of the one or more blocks that is detected to be free of null data; and

generate and execute, by the data processing framework, non-optimized code for each block of the one or more blocks that is detected to include null data such that an original format of the one or more blocks detected to include the null data is maintained,

wherein metadata is created for each block of the one or more blocks when an in-memory structure is created; and

wherein the determining is employed when a schema is updated.

10. The computer system of claim 9 , wherein the data processing framework is a cluster computing engine.

11. The computer system of claim 9 , wherein further metadata is created for each block of the one or more blocks when a file is created.

12. The computer system of claim 9 , wherein, when executing a subquery, the determining is employed to an output of the subquery.

13. The computer system of claim 9 , wherein the determining is employed when an index is created.

14. The computer system of claim 9 , wherein the determining is employed when a query is executed, the query scanning a part of a column or a whole column.

15. A non-transitory computer readable storage medium comprising a computer readable program for improving performance of data processing with nullable schema information by using a data processing framework, wherein the computer readable program when executed on a computer causes the computer to perform the steps of:

reading, by the processor, data from one or more blocks forming a column, where the data is stored in a database including the one or more blocks;

determining, by the processor, whether any row in each block of the one or more blocks includes null data;

generating and executing, by the data processing framework, optimized code for each block of the one or more blocks that is detected to be free of null data;

generating and executing, by the data processing framework, non-optimized code for each block of the one or more blocks that is detected to include null data such that an original format of the one or more blocks detected to include the null data is maintained;

creating metadata for each block of the one or more blocks when an in-memory structure is created; and

employing the determining step when a schema is updated.

16. The computer readable storage medium of claim 15 , wherein metadata is further created for each block of the one or more blocks when a file is created.