{"id":1490,"date":"2009-04-22T12:00:00","date_gmt":"2009-04-22T12:00:00","guid":{"rendered":"http:\/\/orcldoug.com\/blog\/?p=1490"},"modified":"2009-04-22T12:00:00","modified_gmt":"2009-04-22T12:00:00","slug":"how-to-generate-more-logical-reads","status":"publish","type":"post","link":"http:\/\/orcldoug.com\/blog\/2009\/04\/22\/how-to-generate-more-logical-reads\/","title":{"rendered":"How to generate more Logical Reads"},"content":{"rendered":"<p>(With my tongue starting to feel a little tired &#8230;)<\/p>\n<p>Mmmm, there\u2019s a table that the application is accessing extremely frequently, called R_DUMMY. I wonder what data it contains?<\/p>\n<pre>SQL&gt; SELECT dummy_key FROM r_dummy;\n\nDUMMY\n-----\nDUMMY<\/pre>\n<p>Mmmm, that looks familiar, doesn\u2019t it? It\u2019s almost like the DUAL table, isn\u2019t it?<\/p>\n<p>\u00a0<\/p>\n<p><a href=\"http:\/\/www.oracle-developer.net\/display.php?id=315\">FAST DUAL optimisation<\/a>? We don\u2019t need no stinkin\u2019 FAST DUAL optimisation.<\/p>\n<p>Sigh.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>(With my tongue starting to feel a little tired &#8230;) Mmmm, there\u2019s a table that the application is accessing extremely frequently, called R_DUMMY. I wonder what data it contains? SQL&gt; SELECT dummy_key FROM r_dummy; DUMMY &#8212;&#8211; DUMMY Mmmm, that looks familiar, doesn\u2019t it? It\u2019s almost like the DUAL table, isn\u2019t it? \u00a0 FAST DUAL optimisation?&hellip; <a class=\"more-link\" href=\"http:\/\/orcldoug.com\/blog\/2009\/04\/22\/how-to-generate-more-logical-reads\/\">Continue reading <span class=\"screen-reader-text\">How to generate more Logical Reads<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-1490","post","type-post","status-publish","format-standard","hentry","category-uncategorized","entry"],"jetpack_featured_media_url":"","jetpack-related-posts":[{"id":1495,"url":"http:\/\/orcldoug.com\/blog\/2009\/05\/01\/diagnosing-locking-problems-using-ashlogminer-the-end\/","url_meta":{"origin":1490,"position":0},"title":"Diagnosing Locking Problems using ASH\/LogMiner \u2013 The End","date":"May 1, 2009","format":false,"excerpt":"Except\u00a0it's not the\u00a0end, of course. What I mean is\u00a0that I usually agree with\u00a0what Miladin Modrakovic said in one of his comments on his first deadlock blog post.\"There is always way around.\"As I keep saying, there are many different ways of diagnosing locking problems. Which one works best\u00a0depends on the situation\u2026","rel":"","context":"Similar post","img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1481,"url":"http:\/\/orcldoug.com\/blog\/2009\/04\/09\/diagnosing-locking-problems-using-ash-part-4\/","url_meta":{"origin":1490,"position":1},"title":"Diagnosing Locking Problems using ASH \u2013 Part 4","date":"April 9, 2009","format":false,"excerpt":"Some features in this post require a Diagnostics Pack license.No sooner had I finished part 3 with some conclusions than I thought of another example I should have included and then someone else made a comment in an email which suggested another. (Thanks, JB!) \"It's probably worth pointing out that\u2026","rel":"","context":"Similar post","img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":953,"url":"http:\/\/orcldoug.com\/blog\/2005\/08\/17\/more-on-and-catpatch-sql\/","url_meta":{"origin":1490,"position":2},"title":"More on ? and catpatch.sql","date":"August 17, 2005","format":false,"excerpt":"When I was writing about the ? shortcut in sqlplus, I half-remembered that I'd discovered this while some time ago while looking at Oracle-supplied scripts (always a useful learning experience). So I went to check that I was right that Oracle uses this and couldn't find an example. Annoying, because\u2026","rel":"","context":"Similar post","img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1084,"url":"http:\/\/orcldoug.com\/blog\/2006\/09\/17\/test-code-examples\/","url_meta":{"origin":1490,"position":3},"title":"Test Code Examples","date":"September 17, 2006","format":false,"excerpt":"Here's a code example with <pre> tags around it. There should be extra spacing between the query and the result than the two lines of the query.SELECT 'Spiders are deadly'FROM DUAL;Spiders are deadlyAnd here is the entire HTML fragment from above <p>Here's a code example with <pre> tags around it.\u2026","rel":"","context":"With 6 comments","img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":926,"url":"http:\/\/orcldoug.com\/blog\/2005\/10\/24\/intel-isp4400\/","url_meta":{"origin":1490,"position":4},"title":"Intel ISP4400","date":"October 24, 2005","format":false,"excerpt":"I've wanted to carry on investigating parallel execution for a while but, unless you happen to be working on a reasonably large data warehouse with a few spare test environments kicking around, it's difficult. Without wishing to reopen the whole debate about the value of single user test scripts (which\u2026","rel":"","context":"With 8 comments","img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":871,"url":"http:\/\/orcldoug.com\/blog\/2006\/01\/31\/basic-blocking-lock-detection\/","url_meta":{"origin":1490,"position":5},"title":"Basic Blocking Lock Detection","date":"January 31, 2006","format":false,"excerpt":"At work today we had a trouble ticket generated by BMC Patrol that complained of a 'Locking Conflict'. Having no idea what this might mean, one of my colleagues (who is learning Oracle) asked how we'd detect a locking problem.Because we were in a hurry, I fell back on a\u2026","rel":"","context":"With 11 comments","img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"_links":{"self":[{"href":"http:\/\/orcldoug.com\/blog\/wp-json\/wp\/v2\/posts\/1490","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/orcldoug.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/orcldoug.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/orcldoug.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/orcldoug.com\/blog\/wp-json\/wp\/v2\/comments?post=1490"}],"version-history":[{"count":0,"href":"http:\/\/orcldoug.com\/blog\/wp-json\/wp\/v2\/posts\/1490\/revisions"}],"wp:attachment":[{"href":"http:\/\/orcldoug.com\/blog\/wp-json\/wp\/v2\/media?parent=1490"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/orcldoug.com\/blog\/wp-json\/wp\/v2\/categories?post=1490"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/orcldoug.com\/blog\/wp-json\/wp\/v2\/tags?post=1490"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}