{"id":15931373,"url":"https://github.com/cfelde/coherencebloom","last_synced_at":"2025-04-03T14:22:15.046Z","repository":{"id":72533331,"uuid":"11937137","full_name":"cfelde/CoherenceBloom","owner":"cfelde","description":"An example Oracle Coherence Bloom filter based reverse index implementation.","archived":false,"fork":false,"pushed_at":"2013-08-07T00:10:09.000Z","size":124,"stargazers_count":2,"open_issues_count":0,"forks_count":2,"subscribers_count":4,"default_branch":"master","last_synced_at":"2025-02-09T03:15:59.940Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":null,"language":"Java","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"lgpl-3.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/cfelde.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null}},"created_at":"2013-08-06T23:42:58.000Z","updated_at":"2014-03-10T06:54:09.000Z","dependencies_parsed_at":"2023-02-21T23:55:43.668Z","dependency_job_id":null,"html_url":"https://github.com/cfelde/CoherenceBloom","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/cfelde%2FCoherenceBloom","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/cfelde%2FCoherenceBloom/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/cfelde%2FCoherenceBloom/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/cfelde%2FCoherenceBloom/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/cfelde","download_url":"https://codeload.github.com/cfelde/CoherenceBloom/tar.gz/refs/heads/master","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":247014710,"owners_count":20869426,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-10-07T01:20:42.061Z","updated_at":"2025-04-03T14:22:15.027Z","avatar_url":"https://github.com/cfelde.png","language":"Java","funding_links":[],"categories":[],"sub_categories":[],"readme":"CoherenceBloom\n==============\n\nAn example Oracle Coherence Bloom filter based reverse index implementation.\n\nTo quote Wikipedia: A Bloom filter is a space-efficient probabilistic data structure that is used to test whether an element is a member of a set.\n\nThis is often used by systems in order to avoid accessing slow media, like a disk. Take HBase or Cassandra for instance: Instead of reading their data files in order to figure out if a particular key is present in a file, a file which might be huge, they can first consult their Bloom filters and get a true/false on if the key is likely to be in there. I say likely because a Bloom filter isn’t guaranteed to be correct. More formally: False positives are possible, but false negatives are not.\n\nGiven that false negatives can’t happen, the worst we’ll do is read a file we didn’t have to read. But we’re also guaranteed to read the file is the key is present, which is the type of guarantee we need.\n\nUsing a similar technique I managed to get almost a 2x performance gain on Oracle Coherence using a custom Bloom filter based index implementation (versus no index), using just a fraction of the memory a standard index instance would use (a few kB at most).\n\nMore info at http://blog.cfelde.com/2013/08/space-efficient-bloom-filter-index-2x-performance-gain/\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fcfelde%2Fcoherencebloom","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fcfelde%2Fcoherencebloom","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fcfelde%2Fcoherencebloom/lists"}