Hi @Chong ,
This will also reduce the file size in secondary server, right?
Normally yes, I tested it before and it worked so, but if you have configured your secondary in Norecovery mode then it won't work. You can check this link: https://social.msdn.microsoft.com/Forums/sqlserver/en-US/8f4a788d-f633-41f2-8632-63f68e2a7b62/shrinking-data-file-on-primary-server-does-not-shrink-data-file-on-logshipping-server?forum=sqldatabaseengine
We need to disable log shipping and remove the DB and log, then rebuild the log shipping? Can we just resume the log shipping by some configuration?
Pls check the two links: https://dba.stackexchange.com/questions/69959/how-do-i-resume-log-shipping
And I think that doing the FULL BACKUP may prevent accident happen.