Vertica 5156 Error.

Hi,
Need help urgently.

I am updating one table and it keeps on showing below error:

"ERROR 5156:  Unavailable: initiator locks for query - Locking failure: Timed out X locking Table:cdr_p.ckm_customer. X held by [user srvc_cdradm (MERGE /*+ direct */ INTO cdr_p.ckm_customer cust"

Well the scenario is there is another table say table b, which takes values from above table and update.. i.e table b depends on ckm table...but at this pt. there r no other tables getting loaded and table b also loaded..thn y not locks r getting released..

Thanks