Re: how to test locks

enzoweb_at_hotmail.com (Andy) wrote in message news:<8d4033cd.0201231501.2f4e1cc1_at_posting.google.com>...
> If you have access to Metalink, there is a good faq on locking.
>
> Go to the Advanced Search and put this in the search field:
>
> Note:15476.1
>
> and click on the "Doc ID" thingy.

  <<snip>>

> > > >
> > > > That is very simple and I'm sure that the most of us here do that every
> day:
> > > > you find the database block for that record (rowid contains file and block
> > > > id), dump the block from oradebug and see whether the row header contains
> > > > the pointer to a valid ITL in that block. The very first byte of the row
> > > > header is the offset into the ITL table. ITLs are 23 bytes in size and
> > > > contain a XID of the transaction that is interested in the block. After
> > > > you do that, ask yourself whether the obtained information was worth the
> > > > trouble. Oh yes, and exact descriptions on the database blocks can be
> > > > obtained only in the Scott Gosset's "top gun" class.
> > > > Oh, did I forget to mention that you have to check whether the block is in
> > > > SGA (v$bh) and if it is, then you have to look there. ITLs in the disk
> > > > block may contain invalid information and be scheduled for "delayed
> > > > cleanup". It's a very simple thing indeed.
> >
> > Could we make our answers a little bit clear and simpler for
> > those who may really need our help.?
> > Thanks

Here is an article at the cooperative FAQ about finding all the locked rows in a table that has a pl/sql code example with error handling that may be of interest to this discussion:

article How do you identify all locked rows in a table ? url http://www.jlcomp.demon.co.uk/faq/locked_rows.html

• Mark D Powell --