{"title":"The input/output complexity of triangle enumeration","authors":"R. Pagh, Francesco Silvestri","doi":"10.1145/2594538.2594552","DOIUrl":null,"url":null,"abstract":"We consider the well-known problem of enumerating all triangles of an undirected graph. Our focus is on determining the input/output (I/O) complexity of this problem. Let E be the number of edges, M<E the size of internal memory, and B the block size. The best results obtained previously are sortE3/2) I/Os (Dementiev, PhD thesis 2006) and O(E2/MB) I/Os (Hu et al., SIGMOD 2013), where sort(n) denotes the number of I/Os for sorting n items. We improve the I/O complexity to O(E3/2/(√MB) expected I/Os, which improves the previous bounds by a factor min(√E/M),√M). Our algorithm is cache-oblivious and also I/O optimal: We show that any algorithm enumerating t distinct triangles must always use Ω(√MB) I/Os, and there are graphs for which t=Ω(E3/2). Finally, we give a deterministic cache-aware algorithm using O(E3/2/√MB) I/Os assuming M > Ec for a constant c > 0. Our results are based on a new color coding technique, which may be of independent interest.","PeriodicalId":302451,"journal":{"name":"Proceedings of the 33rd ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems","volume":"8 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2013-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"63","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Proceedings of the 33rd ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1145/2594538.2594552","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 63
Abstract
We consider the well-known problem of enumerating all triangles of an undirected graph. Our focus is on determining the input/output (I/O) complexity of this problem. Let E be the number of edges, M Ec for a constant c > 0. Our results are based on a new color coding technique, which may be of independent interest.