Re: [HACKERS] Lock freeze ? in MVCC - Mailing list pgsql-hackers

From Vadim Mikheev
Subject Re: [HACKERS] Lock freeze ? in MVCC
Date
Msg-id 3726EAA4.FAD4541A@krs.ru
Whole thread Raw
In response to RE: [HACKERS] Lock freeze ? in MVCC  ("Hiroshi Inoue" <Inoue@tpf.co.jp>)
List pgsql-hackers
Hiroshi Inoue wrote:
> 
> >
> > if we already have some lock with priority X and new requested
> > lock has priority Y, Y <= X, then lock must be granted.
> >
> > Also, I would get rid of lockReadPriority stuff...
> >
> 
> I found a problem to get rid of lockReadPriority stuff completely.
> If there's a table which is insert/update/deleted very frequenly by
> several processes,processes which request the high priority lock
> (such as vacuum) could hardly acquire the lock for the table.

I didn't mean to get rid of code checking waiter locks completely.
I just said that condition below
      if (!lockReadPriority)

is unuseful any more.

Read my prev letter when, imo, we have to take waiters into
account.

Vadim


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