Right.. I guess you'd have to look real close at each object and make really sure it's not being used.  It could point you in the right direction I guesss...  You could identify for sure that an object is used, but not be 100% certain an object isn't used...

Thanks, that you get attention to my wording (not many people captured it)

There are several tricks. When you define the suspicious objects that may not be used, you can add simple trigger for select, insert, update with simple insert to log table with info about the table beeng accessed, date, and user. In addition, I am lucky because we adapt the policy and management supporting me with it that all calls (even simple reports with 1 SQL statement) only by stored procedures.

select bucketid, cacheobjtype, objtype, objid, dbid     
 from master.dbo.SYSCACHEOBJECTS
 where  objid = 1718297181

at 10:30 am.

I do not understand why it keep lock the other process.

I do not understand I run the process

select bucketid, cacheobjtype, objtype, objid, dbid     
 from master.dbo.SYSCACHEOBJECTS
 where  objid = 1718297181.

It still lock the  process. My other scheduled task aplication in the server could not run due to the lock. Thanks.

Try running this instead:

select bucketid, cacheobjtype, objtype, objid, dbid     
 from master.dbo.SYSCACHEOBJECTS with(nolock)
 where  objid = 1718297181

Please try to read article carefully before trying.

#1. You can use "nolock" hint

#2. I did exclude where clause from the tests I was doing. Insert all rows to the temporary table and then get the objectid you are looking for. I show it for one object as an example at the beginning of the article. But in reality I never done it on the object by object bases.

Always all records from syscache table and then make an analysis