Snowflake Inc.
Scan set pruning for pattern matching queries

Abstract:

A query directed at a source table organized into a set of batch units is received. The query includes a pattern matching predicate that specifies a search pattern. A set of N-grams are generated based on the search pattern. A pruning index is used to identify a subset of batch units to scan for matching data based on the set of N-grams generated for the search pattern. The pruning index indexes distinct N-grams in the source table. The query is processed by scanning the subset of batch units.