-
Bug
-
-
Critical
-
Resolution:
Fixed
-
N/A
-
-
-
--source include/have_sequence.inc
|
|
create table t1 (a char(1)) engine=MyISAM;
|
insert into t1 select chr(seq%26+97) from seq_1_to_50;
|
insert into t1 select ':' from t1;
|
|
select count(*) from t1 where a <> 'a';
|
|
set histogram_type=JSON_HB;
|
analyze table t1 persistent for all;
|
|
explain format=json select COUNT(*) FROM t1 WHERE a <> 'a';
|
|
set histogram_type=DOUBLE_PREC_HB;
|
analyze table t1 persistent for all;
|
|
explain format=json select COUNT(*) FROM t1 WHERE a <> 'a';
|
|
# Cleanup
|
drop table t1;
|
The result of the query is 99 rows:
select count(*) from t1 where a <> 'a';
|
count(*)
|
99
|
So, the estimation with DOUBLE_PREC_HB is quite close:
preview-10.8-MDEV-26519-json-histograms 98cb4351
|
"query_block": {
|
"select_id": 1,
|
"nested_loop": [
|
{
|
"table": {
|
"table_name": "t1",
|
"access_type": "ALL",
|
"rows": 100,
|
"filtered": 100,
|
"attached_condition": "t1.a <> 'a'"
|
}
|
}
|
]
|
}
|
The estimation with JSON_HB is off:
"query_block": {
|
"select_id": 1,
|
"nested_loop": [
|
{
|
"table": {
|
"table_name": "t1",
|
"access_type": "ALL",
|
"rows": 100,
|
"filtered": 52.70370102,
|
"attached_condition": "t1.a <> 'a'"
|
}
|
}
|
]
|
}
|
- is caused by
-
MDEV-26519
JSON Histograms: improve histogram collection
-
-
Closed
Transition |
Time In Source Status |
Execution Times |
Open |
|
In Progress |
|
1h 50m
|
1
|
In Progress |
|
Closed |
|
2d 53m
|
1
|
{"report":{"fcp":1319.2000000476837,"ttfb":286.90000009536743,"pageVisibility":"visible","entityId":105907,"key":"jira.project.issue.view-issue","isInitial":true,"threshold":1000,"elementTimings":{},"userDeviceMemory":8,"userDeviceProcessors":64,"apdex":0.5,"journeyId":"3e20fdfa-13d9-4f9d-861e-e8e63ec3f201","navigationType":0,"readyForUser":1427.7999999523163,"redirectCount":0,"resourceLoadedEnd":1734.2999999523163,"resourceLoadedStart":314.7999999523163,"resourceTiming":[{"duration":448,"initiatorType":"link","name":"https://jira.mariadb.org/s/2c21342762a6a02add1c328bed317ffd-CDN/lu2cib/820016/12ta74/0a8bac35585be7fc6c9cc5a0464cd4cf/_/download/contextbatch/css/_super/batch.css","startTime":314.7999999523163,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":314.7999999523163,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":762.7999999523163,"responseStart":0,"secureConnectionStart":0},{"duration":447.89999985694885,"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":315.2000000476837,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":315.2000000476837,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":763.0999999046326,"responseStart":0,"secureConnectionStart":0},{"duration":463,"initiatorType":"script","name":"https://jira.mariadb.org/s/0917945aaa57108d00c5076fea35e069-CDN/lu2cib/820016/12ta74/0a8bac35585be7fc6c9cc5a0464cd4cf/_/download/contextbatch/js/_super/batch.js?locale=en","startTime":315.2999999523163,"connectEnd":315.2999999523163,"connectStart":315.2999999523163,"domainLookupEnd":315.2999999523163,"domainLookupStart":315.2999999523163,"fetchStart":315.2999999523163,"redirectEnd":0,"redirectStart":0,"requestStart":315.2999999523163,"responseEnd":778.2999999523163,"responseStart":778.2999999523163,"secureConnectionStart":315.2999999523163},{"duration":542.5,"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":315.59999990463257,"connectEnd":315.59999990463257,"connectStart":315.59999990463257,"domainLookupEnd":315.59999990463257,"domainLookupStart":315.59999990463257,"fetchStart":315.59999990463257,"redirectEnd":0,"redirectStart":0,"requestStart":315.59999990463257,"responseEnd":858.0999999046326,"responseStart":858.0999999046326,"secureConnectionStart":315.59999990463257},{"duration":546.2000000476837,"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":315.7000000476837,"connectEnd":315.7000000476837,"connectStart":315.7000000476837,"domainLookupEnd":315.7000000476837,"domainLookupStart":315.7000000476837,"fetchStart":315.7000000476837,"redirectEnd":0,"redirectStart":0,"requestStart":315.7000000476837,"responseEnd":861.9000000953674,"responseStart":861.9000000953674,"secureConnectionStart":315.7000000476837},{"duration":546.4000000953674,"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":316,"connectEnd":316,"connectStart":316,"domainLookupEnd":316,"domainLookupStart":316,"fetchStart":316,"redirectEnd":0,"redirectStart":0,"requestStart":316,"responseEnd":862.4000000953674,"responseStart":862.4000000953674,"secureConnectionStart":316},{"duration":546.7999999523163,"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":316.2000000476837,"connectEnd":316.2000000476837,"connectStart":316.2000000476837,"domainLookupEnd":316.2000000476837,"domainLookupStart":316.2000000476837,"fetchStart":316.2000000476837,"redirectEnd":0,"redirectStart":0,"requestStart":316.2000000476837,"responseEnd":863,"responseStart":863,"secureConnectionStart":316.2000000476837},{"duration":619.0999999046326,"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":316.40000009536743,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":316.40000009536743,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":935.5,"responseStart":0,"secureConnectionStart":0},{"duration":546.8000001907349,"initiatorType":"script","name":"https://jira.mariadb.org/rest/api/1.0/shortcuts/820016/47140b6e0a9bc2e4913da06536125810/shortcuts.js?context=issuenavigation&context=issueaction","startTime":316.59999990463257,"connectEnd":316.59999990463257,"connectStart":316.59999990463257,"domainLookupEnd":316.59999990463257,"domainLookupStart":316.59999990463257,"fetchStart":316.59999990463257,"redirectEnd":0,"redirectStart":0,"requestStart":316.59999990463257,"responseEnd":863.4000000953674,"responseStart":863.4000000953674,"secureConnectionStart":316.59999990463257},{"duration":619,"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":316.7999999523163,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":316.7999999523163,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":935.7999999523163,"responseStart":0,"secureConnectionStart":0},{"duration":547.1999998092651,"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":316.90000009536743,"connectEnd":316.90000009536743,"connectStart":316.90000009536743,"domainLookupEnd":316.90000009536743,"domainLookupStart":316.90000009536743,"fetchStart":316.90000009536743,"redirectEnd":0,"redirectStart":0,"requestStart":316.90000009536743,"responseEnd":864.0999999046326,"responseStart":864.0999999046326,"secureConnectionStart":316.90000009536743},{"duration":1115.9000000953674,"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":318,"connectEnd":318,"connectStart":318,"domainLookupEnd":318,"domainLookupStart":318,"fetchStart":318,"redirectEnd":0,"redirectStart":0,"requestStart":318,"responseEnd":1433.9000000953674,"responseStart":1433.9000000953674,"secureConnectionStart":318},{"duration":1416.2999999523163,"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":318,"connectEnd":318,"connectStart":318,"domainLookupEnd":318,"domainLookupStart":318,"fetchStart":318,"redirectEnd":0,"redirectStart":0,"requestStart":318,"responseEnd":1734.2999999523163,"responseStart":1734.2999999523163,"secureConnectionStart":318},{"duration":505.7999999523163,"initiatorType":"xmlhttprequest","name":"https://jira.mariadb.org/rest/webResources/1.0/resources","startTime":969.2000000476837,"connectEnd":969.2000000476837,"connectStart":969.2000000476837,"domainLookupEnd":969.2000000476837,"domainLookupStart":969.2000000476837,"fetchStart":969.2000000476837,"redirectEnd":0,"redirectStart":0,"requestStart":969.2000000476837,"responseEnd":1475,"responseStart":1475,"secureConnectionStart":969.2000000476837}],"fetchStart":0,"domainLookupStart":0,"domainLookupEnd":0,"connectStart":0,"connectEnd":0,"requestStart":109,"responseStart":286,"responseEnd":295,"domLoading":293,"domInteractive":1760,"domContentLoadedEventStart":1760,"domContentLoadedEventEnd":1820,"domComplete":3065,"loadEventStart":3065,"loadEventEnd":3065,"userAgent":"Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)","marks":[{"name":"bigPipe.sidebar-id.start","time":1740.9000000953674},{"name":"bigPipe.sidebar-id.end","time":1742.9000000953674},{"name":"bigPipe.activity-panel-pipe-id.start","time":1743},{"name":"bigPipe.activity-panel-pipe-id.end","time":1744},{"name":"activityTabFullyLoaded","time":1834.5}],"measures":[],"correlationId":"9fc579b59d2f61","effectiveType":"4g","downlink":10,"rtt":0,"serverDuration":105,"dbReadsTimeInMs":18,"dbConnsTimeInMs":27,"applicationHash":"9d11dbea5f4be3d4cc21f03a88dd11d8c8687422","experiments":[]}}