Performance issue: Unable To Delete CI's from UI - This action never completes.Issue Unable to delete cmdb records from UI action. Open the record of the CI that needs to be deleted, then click on Delete, and click Delete again to confirm.The form just remains there. After 5 min re-query the same CI and observe that the CI is still there. It does not get deleted. ReleaseAllCauseThe log file shows that the transaction actually got cancelled after 5 minutes. It spent all the time on a "ALTER TABLE sh$cmdb" command and it was cancelled due to maximum execution time exceeded. =============================== 2020-07-29 11:48:49 (112) Default-thread-14 70D08DB1DB96D890890CFABFAA9619DA txid=cb0209b9db96 *** Start #113481 /xmlhttp.do, user: user1 .... 2020-07-29 11:53:47 (618) glide.quota.manager WARNING *** WARNING *** Transaction: Cancelling transaction #113481 /xmlhttp.do (maximum execution time exceeded): Thread Default-thread-14 (user1, 70D08DB1DB96D890890CFABFAA9619DA), after 298515ms 2020-07-29 11:53:47 (904) DBConfigurationControllerSweeperJob{glide.fastlock,glide,glide.ts} WARNING *** WARNING *** Last SQL statement @ 11:48:49.196 : Default-thread-14 (/xmlhttp.do):ALTER TABLE sh$cmdb ADD `u_osu_end_of_support` DATE , ADD `u_osu_planned_os_upgrade_year` VARCHAR(4) , ADD `u_osu_extended_end_of_support` DATE , ADD `u_osu_issue_description` MEDIUMTEXT 2020-07-29 11:53:47 (905) Default-thread-14 70D08DB1DB96D890890CFABFAA9619DA txid=cb0209b9db96 WARNING *** WARNING *** Transaction cancelled: maximum execution time exceeded =============================== This happens because there are a lot of rows in the sh\$cmdb shadow table. Since the shadow table is huge, the ALTER TABLE command takes a lot of time until it gets cancelled. "select count(*) from sh\$cmdb"+------+----------+| Port | count(*) |+------+----------+| 3400 | 10944439 |+------+----------+ "select count(*) from sh\$cmdb\$par1"+------+----------+| Port | count(*) |+------+----------+| 3400 | 10944439 |+------+----------+ ResolutionOld rollback contexts and related data are supposed to be cleaned up automatically however there may be issues that may result in unexpected large tables as reported in known problem PRB1366907 - Scheduled Job "Clean Expired Rollback Contexts" cleans only active expired Rollback Contexts.The fix is to clean up the shadow tables. Contact ServiceNow to request the clean up of shadow tables sh\$cmdb and/or sh\$cmdb\$par1 and let ServiceNow know how much data you want to keep ( for example, you can keep the data generated in the last month - ie. delete everything older than one month ).