Scan set pruning for queries with predicates on semi-structured fields

A database system comprising:

• at least one hardware processor;
• and
• at least one memory storing instructions that cause the at least one hardware processor to perform operations comprising:
• receiving a query including a predicate directed at semi-structured data in a table organized into a set of batch units;
• generating one or more indexing transformations based on a value in the predicate, the generating of the one or more indexing transformations comprising executing a cast function on the value in the predicate to convert the value from a first data type to a second data type;
• pruning, using a pruning index, the set of batch units based on the one or more indexing transformations, the pruning index comprising a set of filters that index distinct values in each column of the table;
• and
• processing the query by scanning a subset of batch units resulting from pruning the set of batch units.

A computer-storage medium comprising instructions that, when executed by one or more processors of a machine, configure the machine to perform operations comprising:

• receiving a query including a predicate directed at semi-structured data in a table organized into a set of batch units;
• generating one or more indexing transformations based on a value in the predicate, the generating of the one or more indexing transformations comprising executing a cast function on the value in the predicate to convert the value from a first data type to a second data type;
• pruning, using a pruning index, the set of batch units based on the one or more indexing transformations, the pruning index comprising a set of filters that index distinct values in each column of the table;
• and
• processing the query by scanning a subset of batch units resulting from pruning the set of batch units.