Message-Id: <10571.113184@fatcity.com> From: "Shockey, David" Date: Thu, 27 Jul 2000 17:42:31 -0500 Subject: RE: Oracle and Record Locking This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01BFF81D.AD4019A4 Content-Type: text/plain; charset="iso-8859-1" Database theorist call this concurrency control and Oracle's means is shared locking, meaning that only one transaction can have the data items selected for update (edit/delete) but other transactions can read the data items. Further, Oracle does not allow uncommitted changes to be read so the readers will see the data items in the same state that the updater begins with. In theory interleaving transactions would be most efficient but there are many possible data integrity problems with interleaving. Jared, is this pedantic? If so, will I be punished? -----Original Message----- From: Abdul Aleem [mailto:abchaudhary-ho@beaconhouse.edu.pk] Sent: Thursday, July 27, 2000 1:06 PM To: Multiple recipients of list ORACLE-L Subject: RE: Oracle and Record Locking Seth Dunehew To my knowledge, FoxPro family of products also do that i.e., records fetched from the tables into a cursor have no relationship with the table. If same record is accessed by two different users, both have rights to update, the effective changes will be of the one who saves later. In oracle, the moment a user initiates editing a record fetched into a form (developer 2000), it is marked as locked (automatically -for third party front-end / back-end this needs manual locking). The locks are automatically released, when the records are committed. I am talking about forms 4.5 and Oracle 8. Don't have any idea about earlier versions. HTH! Aleem -----Original Message----- Sent: 27 July 2000 20:18 To: Multiple recipients of list ORACLE-L Subject: Oracle and Record Locking We have a consultant at our shop who is convinced that Oracle is inadequate for a serious multi-user environment because of the lack of record locking and dynamic result sets. We have been using it to develop and deploy a OLTP system and haven't found any serious problems that could not be addressed. The dynamic result set that he has mentioned has me a little puzzled. He is stating that relational databases that he has worked with in the past returned a result set to him for use in his apps that would change dynamically if another user changed one of the records that he was displaying. I'm a relative newcomer to the database arena, 2 years, but this is something new. I've been told by another developer that Access will do this, but he hadn't heard of any serious systems that do. Has anyone else heard of databases that perform that function? Any suggestions on resources related to record locking in Oracle? We have two other developers that have worked with it extensively in the past, but the consultant is convinced that he knows differently, so we do need some solid research to refute him. Thanks Seth Dunehew -- Author: Seth Dunehew INET: sdunehew@medicalmatrix.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -- Author: Abdul Aleem INET: abchaudhary-ho@beaconhouse.edu.pk Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru@fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). ------_=_NextPart_001_01BFF81D.AD4019A4 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable RE: Oracle and Record Locking

Database theorist call this concurrency control and = Oracle's means is shared locking, meaning that only one transaction can = have the data items selected for update (edit/delete) but other = transactions can read the data items.  Further, Oracle does not = allow uncommitted changes to be read so the readers will see the data = items in the same state that the updater begins with. 

In theory interleaving transactions would be most = efficient but there are many possible data integrity problems with = interleaving. 

Jared, is this pedantic?  If so, will I be = punished?


-----Original Message-----
From: Abdul Aleem [mailto:abchaudhary-ho@= beaconhouse.edu.pk]
Sent: Thursday, July 27, 2000 1:06 PM
To: Multiple recipients of list ORACLE-L
Subject: RE: Oracle and Record Locking


Seth Dunehew

To my knowledge, FoxPro family of products also do = that i.e., records
fetched from the tables into a cursor have no = relationship with the table.
If same record is accessed by two different users, = both have rights to
update, the effective changes will be of the one who = saves later.

In oracle, the moment a user initiates editing a = record fetched into a form
(developer 2000), it is marked as locked = (automatically -for third party
front-end / back-end this needs manual locking). The = locks are automatically
released, when the records are committed. I am = talking about forms 4.5 and
Oracle 8. Don't have any idea about earlier = versions.

HTH!

Aleem

 -----Original Message-----
Sent:   27 July 2000 20:18
To:     Multiple recipients of = list ORACLE-L
Subject:        = Oracle and Record Locking


We have a consultant at our shop who is convinced = that Oracle is inadequate
for a serious multi-user environment because of the = lack of record locking
and dynamic result sets.  We have been using it = to develop and deploy a OLTP
system and haven't found any serious problems that = could not be addressed.

The dynamic result set that he has mentioned has me a = little puzzled.  He is
stating that relational databases that he has worked = with in the past
returned a result set to him for use in his apps = that would change
dynamically if another user changed one of the = records that he was
displaying.  I'm a relative newcomer to the = database arena, 2 years, but
this is something new.  I've been told by = another developer that Access will
do this, but he hadn't heard of any serious systems = that do. 

Has anyone else heard of databases that perform that = function? 

Any suggestions on resources related to record = locking in Oracle?  We have
two other developers that have worked with it = extensively in the past, but
the consultant is convinced that he knows = differently, so we do need some
solid research to refute him.

Thanks

Seth Dunehew
--
Author: Seth Dunehew
  INET: sdunehew@medicalmatrix.com

Fat City Network Services    -- (858) = 538-5051  FAX: (858) 538-5051
San Diego, = California        -- Public Internet = access / Mailing Lists

--
Author: Abdul Aleem
  INET: = abchaudhary-ho@beaconhouse.edu.pk

Fat City Network Services    -- (858) = 538-5051  FAX: (858) 538-5051
San Diego, = California        -- Public Internet = access / Mailing Lists
---------------------------------------------------------------= -----
To REMOVE yourself from this mailing list, send an = E-Mail message
to: ListGuru@fatcity.com (note EXACT spelling of = 'ListGuru') and in
the message BODY, include a line containing: UNSUB = ORACLE-L
(or the name of mailing list you want to be removed =