Re: Locking
From: HansF <News.Hans_at_telus.net>
Date: Fri, 21 Oct 2005 20:50:35 GMT
Message-Id: <pan.2005.10.21.20.49.15.119359_at_telus.net>
>> On Thu, 20 Oct 2005 23:50:58 +0800, Pat interested us by writing:
>>
>> >
>> > in oracle form when user locks a row. some other process which needs
>> > the same row will need to wait until the first user commit/rollback.
>>
>> Depends ENTIRELY on what locks are in place and what lock state the other
>> process needs.
>>
>> For example, even if a process updates a row, other processes will
>> normally be able to read the previous copy (or before begin of
>> transaction copy) of the row without any hesitation. Writers do not block
>> readers and readers do not block writers - under 'normal' circumstances
>> and within 'normal' limits.
>>
>>
> Thanks. instead both processes need to update the same row.
Date: Fri, 21 Oct 2005 20:50:35 GMT
Message-Id: <pan.2005.10.21.20.49.15.119359_at_telus.net>
On Fri, 21 Oct 2005 22:21:22 +0800, Pat interested us by writing:
> > "HansF" <News.Hans_at_telus.net> wrote in message > news:pan.2005.10.20.18.15.50.70906_at_telus.net...
>> On Thu, 20 Oct 2005 23:50:58 +0800, Pat interested us by writing:
>>
>> >
>> > in oracle form when user locks a row. some other process which needs
>> > the same row will need to wait until the first user commit/rollback.
>>
>> Depends ENTIRELY on what locks are in place and what lock state the other
>> process needs.
>>
>> For example, even if a process updates a row, other processes will
>> normally be able to read the previous copy (or before begin of
>> transaction copy) of the row without any hesitation. Writers do not block
>> readers and readers do not block writers - under 'normal' circumstances
>> and within 'normal' limits.
>>
>>
> Thanks. instead both processes need to update the same row.
In that case, the second to the row will wait on the first to commit or rollback.
Sounds like a design issue or flaw if this is a concern.
-- Hans Forbrich Canada-wide Oracle training and consulting mailto: Fuzzy.GreyBeard_at_gmail.com *** I no longer assist with top-posted newsgroup queries ***Received on Fri Oct 21 2005 - 22:50:35 CEST