Thread: LOCK.tag(figuring out granularity of lock)
following is taken from postgresql-7.3.2/src/backend/storage/lmgr/readme: "If we are setting a table level lockboth the blockId and tupleId (in an item pointer this is calledthe position) are setto invalid, if it is a page level lock theblockId is valid, while the tupleId is still invalid. Finally ifthis is a tuplelevel lock (we currently never do this) then boththe blockId and tupleId are set to valid specifications. " how do we check whether blockId and tupleId of LOCK.tag are valid or invalid? is blockId same as tag.objId.blkno? what field in LOCK.tag is tupleId? thanks jenny _________________________________________________________________ Protect your PC - get McAfee.com VirusScan Online http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
"Jenny -" <nat_lazy@hotmail.com> writes: > how do we check whether blockId and tupleId of LOCK.tag are valid or > invalid? Look at how LockRelation and LockPage (in src/backend/storage/lmgr/lmgr.c) set up the tags --- it might be clearer then. regards, tom lane