Hi Vinay,
> Locks will be in place since the rowid stuff is applicable only for
updates
> and deletes. selects obviously cannot work with this! Also, to the best
of
> my knowledge Oracle row ids are fixed unless you move them to new db
i.e.
> export or stuff.
Lazyness is one sort of stupidness, so I tried to be not so stupid
anymore and looked it up ... turned out you are right and I was wrong!
At least since Oracle 7 the ROWID remains fixed and is explicitely
usable for fast access to rows even surviving commits/transactions
and without any need to select ... for update.
See http://technet.oracle.com/doc/server.815/a67781/c10datyp.htm
or read the essential excerpt here:
| Physical rowids provide the fastest possible access to a row of a
| given table. They contain the physical address of a row (down to
| the specific block), and essentially allow you to retrieve the
| row in a single block access. Oracle guarantees that as long as
| the row exists, its rowid does not change. These performance and
| stability qualities make rowids useful for applications that
| select a set of rows, perform some operations on them, and then
| access some of the selected rows again, perhaps with the purpose
| of updating them.
...
| A row's assigned rowid remains unchanged unless the row is
| exported and imported (using the IMPORT and EXPORT utilities).
| When you delete a row from a table (and then commit the
| encompassing transaction), the deleted row's associated rowid can
| be assigned to a row inserted in a subsequent transaction.
...
| A row's logical rowid does not change as long as the primary key
| value does not change. This is less stable than the physical
| rowid, which stays immutable through all updates to the row.
Sorry to have bothered you
regards
Georg
___ ___
| + | |__ Georg Rehfeld Woltmanstr. 12 20097 Hamburg
|_|_\ |___ [EMAIL PROTECTED] +49 (40) 23 53 27 10
_______________________________________________
Jboss-development mailing list
[EMAIL PROTECTED]
http://lists.sourceforge.net/lists/listinfo/jboss-development
