Ever have a DB2 query that all of a sudden went from performing just fine to being dog slow? If so, there may be an issue with the stats on one or more of the tables being used in the query. To check, run the SQL below replacing XX and TABLE_NM with your appropriate schema and table in 2 places…<\/p>\n

-- What DB2 thinks the table count is\r\nSELECT  'Stats' AS TYPE_X,\r\n        CARD AS COUNT_NB,\r\n        STATS_TIME AS UPDATED_TS\r\nFROM    SYSCAT.TABLES \r\nWHERE   TABSCHEMA = 'XX' \r\n        AND TABNAME ='TABLE_NM'\r\n    UNION\r\n-- Actual table count\r\nSELECT  'Actual' AS TYPE_X,\r\n        COUNT(*) AS COUNT_NB,\r\n        CURRENT_TIMESTAMP AS UPDATED_TS\r\nFROM    XX.TABLE_NM\r\nFOR READ ONLY WITH UR\r\n<\/code><\/pre>\n
… if the record counts are way off, have your DBA do a runstats on the table in question followed by a rebind of any stored procs that use the table.<\/p>\nPlease remember to subscribe to the newsletter<\/a> to stay up to date!<\/i>\n\nYou or someone you know looking to buy or sell?<\/i>\n<\/a>\nDisclaimer: Thoughts and opinions are my own, and do not reflect the views of any employer, family member, friend, or anyone else. Some links may be affiliate links, but I don't link to anything I don't use myself. You would think this should be self evident these days, but apparently not...<\/small><\/i>","protected":false},"excerpt":{"rendered":"
Ever have a DB2 query that all of a sudden went from performing just fine to being dog slow? If so, there may be an issue with the stats on one or more of the tables being used in the query. To check, run the SQL below replacing XX and TABLE_NM with your appropriate schema … Continue reading DB2 Stats vs Actual<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"footnotes":"","_jetpack_memberships_contains_paid_content":false,"jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","enabled":false},"version":2}},"categories":[3],"tags":[107,22],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2UXeD-j8","jetpack_sharing_enabled":true,"jetpack-related-posts":[],"jetpack_likes_enabled":false,"_links":{"self":[{"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/posts\/1186"}],"collection":[{"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/comments?post=1186"}],"version-history":[{"count":3,"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/posts\/1186\/revisions"}],"predecessor-version":[{"id":1189,"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/posts\/1186\/revisions\/1189"}],"wp:attachment":[{"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/media?parent=1186"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/categories?post=1186"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/markjacobsen.net\/wp-json\/wp\/v2\/tags?post=1186"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}