Bloom Filter

Bloom filter helps prune segments that do not contain any record matching an EQUALITY predicate.

It would be useful for a query like the following:

SELECT COUNT(*) 
FROM baseballStats 
WHERE playerID = 12345

There are 3 parameters to configure the Bloom Filter:

• fpp: False positive probability of the bloom filter (from 0 to 1, 0.05 by default). The lower the fpp , the higher accuracy the bloom filter has, but it will also increase the size of the bloom filter.

• maxSizeInBytes: Maximum size of the bloom filter (unlimited by default). If a certain fpp generates a bloom filter larger than this size, we will increase the fpp to keep the bloom filter size within this limit.

• loadOnHeap: Whether to load the bloom filter using heap memory or off-heap memory (false by default).

There are 2 ways to configure a bloom filter for a table in the :

• Default settings

• Customized parameters

A Bloom Filter can only be applied to . Support for raw value columns is WIP.