Re: MVCC and all that...
Ron Johnson <ronljohnsonjr@gmail.com>
From: Ron Johnson <ronljohnsonjr@gmail.com>
To: pgsql-general <pgsql-general@postgresql.org>
Date: 2025-09-10T15:55:28Z
Lists: pgsql-general
On Tue, Sep 9, 2025 at 8:41 PM Justin <zzzzz.graf@gmail.com> wrote: [snip] > Multiple transactions per connection. I am asking WHY is that a feature. > when one can have multiple sessions, what is the difference? running > multiple transactions in single or multiple sessions means moving part of > transaction logic into the application space. What do we gain here..... > If I interpret "Multiple transactions per connection" correctly, they're a great way to emulate WITH HOLD cursors. For example: 1. In channel #1, open a Read Only cursor. (Yes, this was long ago.) 2. Fetch a row. 3. Switch to channel #2, begin R/W txn, modify the table, commit. 4. Switch back to channel #1 5. Go to step 2. Not being an application developer anymore, I've never needed to use WITH HOLD cursors or wish for multiple channels in PG. -- Death to <Redacted>, and butter sauce. Don't boil me, I'm still alive. <Redacted> lobster!