{"id":12590,"date":"2021-11-13T17:03:54","date_gmt":"2021-11-13T22:03:54","guid":{"rendered":"https:\/\/carleton.ca\/scs\/?page_id=12590"},"modified":"2026-06-02T14:59:26","modified_gmt":"2026-06-02T18:59:26","slug":"tr-78-improving-semijoin-evaluation-in-distributed-query-processing","status":"publish","type":"page","link":"https:\/\/carleton.ca\/scs\/research\/scs-technical-reports\/technical-reports-1985\/tr-78-improving-semijoin-evaluation-in-distributed-query-processing\/","title":{"rendered":"TR-78: Improving Semijoin Evaluation in Distributed Query Processing"},"content":{"rendered":"\n<section class=\"w-screen px-6 cu-section cu-section--white ml-offset-center md:px-8 lg:px-14\">\n    <div class=\"space-y-6 cu-max-w-child-5xl  md:space-y-10 cu-prose-first-last\">\n\n            <div class=\"cu-textmedia flex flex-col lg:flex-row mx-auto gap-6 md:gap-10 my-6 md:my-12 first:mt-0 max-w-5xl\">\n        <div class=\"justify-start cu-textmedia-content cu-prose-first-last\" style=\"flex: 0 0 100%;\">\n            <header class=\"font-light prose-xl cu-pageheader md:prose-2xl cu-component-updated cu-prose-first-last\">\n                                    <h1 class=\"cu-prose-first-last font-semibold !mt-2 mb-4 md:mb-6 relative after:absolute after:h-px after:bottom-0 after:bg-cu-red after:left-px text-3xl md:text-4xl lg:text-5xl lg:leading-[3.5rem] pb-5 after:w-10 text-cu-black-700 not-prose\">\n                        TR-78: Improving Semijoin Evaluation in Distributed Query Processing\n                    <\/h1>\n                \n                                \n                            <\/header>\n\n                    <\/div>\n\n            <\/div>\n\n    <\/div>\n<\/section>\n\n<p>Carleton University<br>\n<a href=\"https:\/\/carleton.ca\/scs\/research\/scs-technical-reports\/technical-reports-1985\/\">Technical Report<\/a> <strong>TR-78<\/strong><br>\nJuly 1985<\/p>\n\n\n\n<h2 id=\"improving-semijoin-evaluation-in-distributed-query-processing\" class=\"wp-block-heading tr_t1\">Improving Semijoin Evaluation in Distributed Query Processing<\/h2>\n\n\n\n<div class=\"tr_t3\">E.J. Otoo, N. Santoro, D. Rotem<\/div>\n\n\n\n<div>\n<h3>Abstract<\/h3>\n<p>The semi-join operation constitutes the fundamental operation for reducing<br>\nthe volume of data transferred between sites in a distributed query processing. We present a method called &#8220;augmented semi-join&#8221; evaluation technique that mini\u00ad<br>\nmizes the volume of data exchanged between sites in query processing algorithms<br>\nthat relying on semi-join computations. The technique performs some initial pre\u00adprocessing of the common join-attribute values of relations stored at different sites<br>\nin such a way that each site can determine the tuples of the various relations that participate in the join computation for all subsequent queries that compute joins.<br>\nLet jCTql denote the total volume of intersite data transferred to achieve complete reduction of the relations referenced in a query Q by using a semi-join expression<br>\nCTq. Let lo-Q i denote the volume of data exchanged in achieving the same reduc\u00ad<br>\ntion with an augmented semi-join evaluation. Then we have that iaol S 0.5ICTqj always. For some special queries e.g., simple queries, the query can be completely evaluated without semi-join computations, i.e., lol = 0.<\/p>\n<\/div>\n\n\n\n<p><a href=\"https:\/\/carleton.ca\/scs\/wp-content\/uploads\/sites\/260\/TR-78.pdf\">TR-78.pdf<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Carleton University Technical Report TR-78 July 1985 Improving Semijoin Evaluation in Distributed Query Processing E.J. Otoo, N. Santoro, D. Rotem Abstract The semi-join operation constitutes the fundamental operation for reducing the volume of data transferred between sites in a distributed query processing. We present a method called &#8220;augmented semi-join&#8221; evaluation technique that mini\u00ad mizes the [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":11823,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_cu_dining_location_slug":"","footnotes":"","_links_to":"","_links_to_target":""},"cu_page_type":[88],"class_list":["post-12590","page","type-page","status-publish","hentry","cu_page_type-technical-report"],"acf":{"cu_post_thumbnail":false},"_links":{"self":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/12590","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/comments?post=12590"}],"version-history":[{"count":2,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/12590\/revisions"}],"predecessor-version":[{"id":12602,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/12590\/revisions\/12602"}],"up":[{"embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/pages\/11823"}],"wp:attachment":[{"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/media?parent=12590"}],"wp:term":[{"taxonomy":"cu_page_type","embeddable":true,"href":"https:\/\/carleton.ca\/scs\/wp-json\/wp\/v2\/cu_page_type?post=12590"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}