USING PERSISTENT DATA SAMPLES AND QUERY-TIME STATISTICS FOR QUERY OPTIMIZATION

摘要

Techniques for storing and querying graph data in a key-value store are provided. A graph statement (e.g., an RDF graph statement) includes a plurality of values, at least two of which correspond to nodes in a graph. A key is generated based on the graph statement. The key may be generated based on concatenating hash values that are generated based on the plurality of values. The key-value store stores the key. The value that corresponds to the key may be a null or empty value. In response to a graph query (e.g., in SPARQL) that includes one or more query patterns, each of which includes one or more values, a key is generated based on the one or more values and sent to the key-value store, which returns one or more other keys, each of which is a superset of the generated key.

主权项

1. One or more storage media storing instructions which, when executed by one or more processors, cause:
in response to receiving a query that includes one or more query patterns, processing the one or more query patterns against a first data set of a plurality of data sets, each of which is a subset of a particular data set; identifying first results that are based on the one or more query patterns being processed against the first data set; determining, based on one or more criteria, whether to process at least one of the one or more query patterns against another data set of the plurality of data sets; in response to determining to process at least one of the one or more query patterns against another data set, processing one or more of the one or more query patterns against a second data set of the plurality of data sets to produce second results, wherein the second data set is different than the first data set; based on the second results, determining how to process the query against the particular data set.