mysqldump --header --tab wraps the dumping SELECT in UNION ALL + ORDER BY. Which means a filesort (try EXPLAIN), that would make mysqldump notably slower on large tables. This is completely unnecessary, because the ordering of table rows is unimportant.
{"report":{"fcp":993.0999999046326,"ttfb":190.89999961853027,"pageVisibility":"visible","entityId":116043,"key":"jira.project.issue.view-issue","isInitial":true,"threshold":1000,"elementTimings":{},"userDeviceMemory":8,"userDeviceProcessors":64,"apdex":0.5,"journeyId":"0afebac1-50f1-48c2-99ab-3d8e53e448d4","navigationType":0,"readyForUser":1062.5,"redirectCount":0,"resourceLoadedEnd":812,"resourceLoadedStart":196.39999961853027,"resourceTiming":[{"duration":319.6000003814697,"initiatorType":"link","name":"https://jira.mariadb.org/s/2c21342762a6a02add1c328bed317ffd-CDN/lu2cib/820016/12ta74/0a8bac35585be7fc6c9cc5a0464cd4cf/_/download/contextbatch/css/_super/batch.css","startTime":196.39999961853027,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":196.39999961853027,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":516,"responseStart":0,"secureConnectionStart":0},{"duration":319.59999990463257,"initiatorType":"link","name":"https://jira.mariadb.org/s/7ebd35e77e471bc30ff0eba799ebc151-CDN/lu2cib/820016/12ta74/494e4c556ecbb29f90a3d3b4f09cb99c/_/download/contextbatch/css/jira.browse.project,project.issue.navigator,jira.view.issue,jira.general,jira.global,atl.general,-_super/batch.css?agile_global_admin_condition=true&jag=true&jira.create.linked.issue=true&slack-enabled=true&whisper-enabled=true","startTime":196.69999980926514,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":196.69999980926514,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":516.2999997138977,"responseStart":0,"secureConnectionStart":0},{"duration":328.7000002861023,"initiatorType":"script","name":"https://jira.mariadb.org/s/0917945aaa57108d00c5076fea35e069-CDN/lu2cib/820016/12ta74/0a8bac35585be7fc6c9cc5a0464cd4cf/_/download/contextbatch/js/_super/batch.js?locale=en","startTime":196.7999997138977,"connectEnd":196.7999997138977,"connectStart":196.7999997138977,"domainLookupEnd":196.7999997138977,"domainLookupStart":196.7999997138977,"fetchStart":196.7999997138977,"redirectEnd":0,"redirectStart":0,"requestStart":196.7999997138977,"responseEnd":525.5,"responseStart":525.5,"secureConnectionStart":196.7999997138977},{"duration":394.09999990463257,"initiatorType":"script","name":"https://jira.mariadb.org/s/2d8175ec2fa4c816e8023260bd8c1786-CDN/lu2cib/820016/12ta74/494e4c556ecbb29f90a3d3b4f09cb99c/_/download/contextbatch/js/jira.browse.project,project.issue.navigator,jira.view.issue,jira.general,jira.global,atl.general,-_super/batch.js?agile_global_admin_condition=true&jag=true&jira.create.linked.issue=true&locale=en&slack-enabled=true&whisper-enabled=true","startTime":197,"connectEnd":197,"connectStart":197,"domainLookupEnd":197,"domainLookupStart":197,"fetchStart":197,"redirectEnd":0,"redirectStart":0,"requestStart":197,"responseEnd":591.0999999046326,"responseStart":591.0999999046326,"secureConnectionStart":197},{"duration":398,"initiatorType":"script","name":"https://jira.mariadb.org/s/a9324d6758d385eb45c462685ad88f1d-CDN/lu2cib/820016/12ta74/c92c0caa9a024ae85b0ebdbed7fb4bd7/_/download/contextbatch/js/atl.global,-_super/batch.js?locale=en","startTime":197.19999980926514,"connectEnd":197.19999980926514,"connectStart":197.19999980926514,"domainLookupEnd":197.19999980926514,"domainLookupStart":197.19999980926514,"fetchStart":197.19999980926514,"redirectEnd":0,"redirectStart":0,"requestStart":197.19999980926514,"responseEnd":595.1999998092651,"responseStart":595.1999998092651,"secureConnectionStart":197.19999980926514},{"duration":398.2000002861023,"initiatorType":"script","name":"https://jira.mariadb.org/s/d41d8cd98f00b204e9800998ecf8427e-CDN/lu2cib/820016/12ta74/1.0/_/download/batch/jira.webresources:calendar-en/jira.webresources:calendar-en.js","startTime":197.39999961853027,"connectEnd":197.39999961853027,"connectStart":197.39999961853027,"domainLookupEnd":197.39999961853027,"domainLookupStart":197.39999961853027,"fetchStart":197.39999961853027,"redirectEnd":0,"redirectStart":0,"requestStart":197.39999961853027,"responseEnd":595.5999999046326,"responseStart":595.5999999046326,"secureConnectionStart":197.39999961853027},{"duration":398.2999997138977,"initiatorType":"script","name":"https://jira.mariadb.org/s/d41d8cd98f00b204e9800998ecf8427e-CDN/lu2cib/820016/12ta74/1.0/_/download/batch/jira.webresources:calendar-localisation-moment/jira.webresources:calendar-localisation-moment.js","startTime":197.59999990463257,"connectEnd":197.59999990463257,"connectStart":197.59999990463257,"domainLookupEnd":197.59999990463257,"domainLookupStart":197.59999990463257,"fetchStart":197.59999990463257,"redirectEnd":0,"redirectStart":0,"requestStart":197.59999990463257,"responseEnd":595.8999996185303,"responseStart":595.8999996185303,"secureConnectionStart":197.59999990463257},{"duration":477.5,"initiatorType":"link","name":"https://jira.mariadb.org/s/b04b06a02d1959df322d9cded3aeecc1-CDN/lu2cib/820016/12ta74/a2ff6aa845ffc9a1d22fe23d9ee791fc/_/download/contextbatch/css/jira.global.look-and-feel,-_super/batch.css","startTime":197.89999961853027,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":197.89999961853027,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":675.3999996185303,"responseStart":0,"secureConnectionStart":0},{"duration":398.19999980926514,"initiatorType":"script","name":"https://jira.mariadb.org/rest/api/1.0/shortcuts/820016/47140b6e0a9bc2e4913da06536125810/shortcuts.js?context=issuenavigation&context=issueaction","startTime":198.09999990463257,"connectEnd":198.09999990463257,"connectStart":198.09999990463257,"domainLookupEnd":198.09999990463257,"domainLookupStart":198.09999990463257,"fetchStart":198.09999990463257,"redirectEnd":0,"redirectStart":0,"requestStart":198.09999990463257,"responseEnd":596.2999997138977,"responseStart":596.2999997138977,"secureConnectionStart":198.09999990463257},{"duration":477.40000009536743,"initiatorType":"link","name":"https://jira.mariadb.org/s/3ac36323ba5e4eb0af2aa7ac7211b4bb-CDN/lu2cib/820016/12ta74/d176f0986478cc64f24226b3d20c140d/_/download/contextbatch/css/com.atlassian.jira.projects.sidebar.init,-_super,-project.issue.navigator,-jira.view.issue/batch.css?jira.create.linked.issue=true","startTime":198.19999980926514,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":198.19999980926514,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":675.5999999046326,"responseStart":0,"secureConnectionStart":0},{"duration":398.7000002861023,"initiatorType":"script","name":"https://jira.mariadb.org/s/5d5e8fe91fbc506585e83ea3b62ccc4b-CDN/lu2cib/820016/12ta74/d176f0986478cc64f24226b3d20c140d/_/download/contextbatch/js/com.atlassian.jira.projects.sidebar.init,-_super,-project.issue.navigator,-jira.view.issue/batch.js?jira.create.linked.issue=true&locale=en","startTime":198.2999997138977,"connectEnd":198.2999997138977,"connectStart":198.2999997138977,"domainLookupEnd":198.2999997138977,"domainLookupStart":198.2999997138977,"fetchStart":198.2999997138977,"redirectEnd":0,"redirectStart":0,"requestStart":198.2999997138977,"responseEnd":597,"responseStart":597,"secureConnectionStart":198.2999997138977},{"duration":612.1999998092651,"initiatorType":"script","name":"https://jira.mariadb.org/s/d41d8cd98f00b204e9800998ecf8427e-CDN/lu2cib/820016/12ta74/1.0/_/download/batch/jira.webresources:bigpipe-js/jira.webresources:bigpipe-js.js","startTime":199.5,"connectEnd":199.5,"connectStart":199.5,"domainLookupEnd":199.5,"domainLookupStart":199.5,"fetchStart":199.5,"redirectEnd":0,"redirectStart":0,"requestStart":199.5,"responseEnd":811.6999998092651,"responseStart":811.6999998092651,"secureConnectionStart":199.5},{"duration":612.5,"initiatorType":"script","name":"https://jira.mariadb.org/s/d41d8cd98f00b204e9800998ecf8427e-CDN/lu2cib/820016/12ta74/1.0/_/download/batch/jira.webresources:bigpipe-init/jira.webresources:bigpipe-init.js","startTime":199.5,"connectEnd":199.5,"connectStart":199.5,"domainLookupEnd":199.5,"domainLookupStart":199.5,"fetchStart":199.5,"redirectEnd":0,"redirectStart":0,"requestStart":199.5,"responseEnd":812,"responseStart":812,"secureConnectionStart":199.5},{"duration":78.09999990463257,"initiatorType":"xmlhttprequest","name":"https://jira.mariadb.org/rest/webResources/1.0/resources","startTime":702.6999998092651,"connectEnd":702.6999998092651,"connectStart":702.6999998092651,"domainLookupEnd":702.6999998092651,"domainLookupStart":702.6999998092651,"fetchStart":702.6999998092651,"redirectEnd":0,"redirectStart":0,"requestStart":702.6999998092651,"responseEnd":780.7999997138977,"responseStart":780.7999997138977,"secureConnectionStart":702.6999998092651}],"fetchStart":0,"domainLookupStart":0,"domainLookupEnd":0,"connectStart":0,"connectEnd":0,"requestStart":14,"responseStart":191,"responseEnd":192,"domLoading":194,"domInteractive":1149,"domContentLoadedEventStart":1149,"domContentLoadedEventEnd":1196,"domComplete":1500,"loadEventStart":1500,"loadEventEnd":1500,"userAgent":"Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)","marks":[{"name":"bigPipe.sidebar-id.start","time":1129.3999996185303},{"name":"bigPipe.sidebar-id.end","time":1130.1999998092651},{"name":"bigPipe.activity-panel-pipe-id.start","time":1130.2999997138977},{"name":"bigPipe.activity-panel-pipe-id.end","time":1131.5999999046326},{"name":"activityTabFullyLoaded","time":1212.7999997138977}],"measures":[],"correlationId":"86f04323d8eb36","effectiveType":"4g","downlink":10,"rtt":0,"serverDuration":112,"dbReadsTimeInMs":15,"dbConnsTimeInMs":25,"applicationHash":"9d11dbea5f4be3d4cc21f03a88dd11d8c8687422","experiments":[]}}
Bug
Critical
MDEV-22200 mysqldump client: --tab export with column names header row
