Bloom Filter

Bloom filter helps prune segments that do not contain any record matching a EQUALITY predicate, e.g.
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 of configuring bloom filter for a table in the table config:
Configure bloom filter columns with default settings
1
{
2
  "tableIndexConfig": {
3
    "bloomFilterColumns": [
4
      "playerID",
5
      ...
6
    ],
7
    ...
8
  },
9
  ...
10
}
Copied!
Configure bloom filter columns with customized parameters
1
{
2
  "tableIndexConfig": {
3
    "bloomFilterConfigs": {
4
      "playerID": {
5
        "fpp": 0.01,
6
        "maxSizeInBytes": 1000000,
7
        "loadOnHeap": true
8
      },
9
      ...
10
    },
11
    ...
12
  },
13
  ...
14
}
Copied!
Currently bloom filter can only be applied to the dictionary-encoded columns. Bloom filter support for raw value columns is WIP.

Star-Tree Index

Range Index

Last modified 11mo ago

Copy link