[Info-vax] RDB Question

[Dave Froble]

On 12/4/2018 8:26 AM, Arne Vajhøj wrote:
> On 12/3/2018 11:10 PM, Dave Froble wrote:
>> On 12/3/2018 9:50 PM, Kerry Main wrote:
>>> Also, Rdb supports row level locking which is a pretty big performance
>>> feature that some DB's do not support.
>>
>> Why do we need different names for things.  Not that I've ever used
>> Rdb, but, isn't that basically the same as a record lock?
>
> Yes.
>
>> And without that, I'm not sure I'd want to use a RDBMS ....
>
> It works without.
>
> Note that we are not talking  functionality of record locking
> vs functionality of no locking.
>
> We are talking performance impact of database locking rows vs
> performance impact of database locking pages.
>
> Both support the integrity of the database.
>
> But in some cases the performance is better if the
> database can lock individual rows instead of locking
> pages (8 KB or whatever chunks).
>
> Arne
>

Well, as usual, mouth spoke before brain engaged.

Same old territory for me.

My database product does not actually lock records, it locks blocks, 
based upon the size of the I/O buffer.

To actually lock records is a much tougher task, and might require 
something like the numeric range locking that was discussed here a while 
back.  This is something that I'm looking forward to in the future, when 
persistent memory and updates in memory are implemented.  "Lock this 
RECORD and do not impact any other operations."

Not being a HW type, I have no idea if there may be reasons to work on 
whole pages rather than a range of bytes.  From a software perspective, 
the "record lock" does appeal to me.


-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
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