rocksdb/docs/static/images/bloom_fp_vs_bpk.png
Peter Dillinger 4b86fe1123 Log warning for high bits/key in legacy Bloom filter (#6312)
Summary:
Help users that would benefit most from new Bloom filter
implementation by logging a warning that recommends the using
format_version >= 5.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6312

Test Plan:
$ (for BPK in 10 13 14 19 20 50; do ./filter_bench -quick -impl=0 -bits_per_key=$BPK -m_queries=1 2>&1; done) | grep 'its/key'
    Bits/key actual: 10.0647
    Bits/key actual: 13.0593
    [WARN] [/block_based/filter_policy.cc:546] Using legacy Bloom filter with high (14) bits/key. Significant filter space and/or accuracy improvement is available with format_verion>=5.
    Bits/key actual: 14.0581
    [WARN] [/block_based/filter_policy.cc:546] Using legacy Bloom filter with high (19) bits/key. Significant filter space and/or accuracy improvement is available with format_verion>=5.
    Bits/key actual: 19.0542
    [WARN] [/block_based/filter_policy.cc:546] Using legacy Bloom filter with high (20) bits/key. Dramatic filter space and/or accuracy improvement is available with format_verion>=5.
    Bits/key actual: 20.0584
    [WARN] [/block_based/filter_policy.cc:546] Using legacy Bloom filter with high (50) bits/key. Dramatic filter space and/or accuracy improvement is available with format_verion>=5.
    Bits/key actual: 50.0577

Differential Revision: D19457191

Pulled By: pdillinger

fbshipit-source-id: 073d94cde5c70e03a160f953e1100c15ea83eda4
2020-01-17 19:37:35 -08:00

51 KiB
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