asdf2014 commented on a change in pull request #6904: add bloom filter druid expression URL: https://github.com/apache/incubator-druid/pull/6904#discussion_r250483168
########## File path: docs/content/development/extensions-core/bloom-filter.md ########## @@ -58,18 +58,29 @@ Internally, this implementation of bloom filter uses Murmur3 fast non-cryptograp ### Serialized Format for BloomKFilter + Serialized BloomKFilter format: + - 1 byte for the number of hash functions. - 1 big endian int(That is how OutputStream works) for the number of longs in the bitset - big endian longs in the BloomKFilter bitset Note: `org.apache.hive.common.util.BloomKFilter` provides a serialize method which can be used to serialize bloom filters to outputStream. ### SQL Queries + Bloom filters are supported in SQL via the `bloom_filter_test` operator: ```sql -SELECT COUNT(*) FROM druid.foo WHERE bloom_filter_test(<dimension>, '<serialized_bytes_for_BloomKFilter>') +SELECT COUNT(*) FROM druid.foo WHERE bloom_filter_test(<expr>, '<serialized_bytes_for_BloomKFilter>') ``` -Expression virtual columns are not currently supported for the `dimension` parameter. + +### Expression and Virtual Column Support + +The bloom filter extension also adds a bloom filter [Druid expression](../../misc/math-expr.html) which shares syntax +with the SQL operator. + +``` Review comment: Please add the `sql` type for this block ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
