List:General Discussion« Previous MessageNext Message »
From:Dan Nelson Date:July 13 2000 3:02pm
Subject:Re: BUG?: BDB
View as plain text  
In the last episode (Jul 13), Tim Bunce said:
> On Thu, Jul 13, 2000 at 02:51:40PM +0300, Michael Widenius wrote:
> > The problem is that BDB uses page locks to guard against multiple
> > transactions and this is what you are seeing.
> > 
> > On big databases, this is not normally noticeable, but it's notable
> > on small tables like in your example.
> 
> And a standard workaround is to pad the row to be the size of a page
> by adding a dummy char field. (Assuming it's a fixed width table,
> else use multiple long int fields.)

But in Pavel's case, it doesn't matter how you pad, because the hanging
query was a "select *", which isn't a transaction.  During a
transaction, there should only be a _write_ lock on the affected pages,
right?  Reads from the table should use the rollback information to
present a view of the table as it was before the transaction was
started.

-- 
	Dan Nelson
	dnelson@stripped
Thread
BUG?: BDBdana42011 Jul
  • Re: BUG?: BDB(Pavel Janík ml.)12 Jul
    • Re: BUG?: BDBDana Powers12 Jul
    • Re: BUG?: BDBMichael Widenius13 Jul
      • Re: BUG?: BDBTim Bunce13 Jul
        • Re: BUG?: BDBRiccardo Pizzi13 Jul
        • Re: BUG?: BDBDan Nelson13 Jul
  • BUG?: BDBMichael Widenius12 Jul
  • Re: BUG?: BDB(Pavel Janík ml.)12 Jul
    • Re: BUG?: BDBDana Powers12 Jul