Re: Really unique session ID - PID + connection timestamp?

From: "durumdara(at)gmail(dot)com" <durumdara(at)gmail(dot)com>
To:
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: Really unique session ID - PID + connection timestamp?
Date: 2016-04-10 13:29:59
Message-ID: 570A5557.9000808@gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general


Dear Alban!

2016.04.10. 13:05 keltezéssel, Alban Hertroys írta:
>> On 10 Apr 2016, at 9:07, Durumdara <durumdara(at)gmail(dot)com> wrote:
>>
>> Dear Adrian!
>>
>> Again. As I see the beginning blocks are removed by mailing system in the code.
>>
>> We have an "ourlocks" table which hold records (TableName, RecordID, SessionInnerID, TimeStamp, etc, with TableName/RecordID prikey).
>>
>> If anybody wants to lock record "for long time", "over the transactions" it try to insert a new record here.
> Why are those records being locked? Reading on, it seems like you're trying to solve a fairly standard concurrency problem. Any RDBMS worth their salt can handle that for you, you don't need to manually do any of that.

This is not real locks. They are logical locks.
Products, offers are edited for long time.
But we must save subdata. This is not a "word like document" which can
saved at once, in a transaction.
When a product edited, we must protect it from other user's edit.
But it's subdata must be posted/commited to the DB, for example
shipping, article quantity changes, vouchers, etc.

>
> This sounds much more like a use-case for sub-transactions and select for update (which puts a temporary RDBMS-controlled lock on the relevant records) than for manual locking.

Yes, this is like sub-transaction.
But for only sub-data. The main data must be edited by only the first
user who started the edit.
This is a long time "lock" like thing. This what we simulate here.

Thanks for your suggestions. I will check this in our client library.

dd

In response to

Responses

Browse pgsql-general by date

  From Date Subject
Next Message Tom Lane 2016-04-10 14:29:02 Re: max_stack_depth problem though query is substantially smaller
Previous Message Alban Hertroys 2016-04-10 11:05:25 Re: Really unique session ID - PID + connection timestamp?