Skip site navigation (1) Skip section navigation (2)

Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and

From: Andrew Dunstan <andrew(at)dunslane(dot)net>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: simon(at)2ndquadrant(dot)com, pgman(at)candle(dot)pha(dot)pa(dot)us, kleptog(at)svana(dot)org, gsstark(at)mit(dot)edu, pg(at)rbt(dot)ca, zhouqq(at)cs(dot)toronto(dot)edu, pgsql-hackers(at)postgresql(dot)org
Subject: Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and
Date: 2005-12-30 17:39:21
Message-ID: 43B570C9.6060406@dunslane.net (view raw or flat)
Thread:
Lists: pgsql-hackers

Tom Lane wrote:

>"Andrew Dunstan" <andrew(at)dunslane(dot)net> writes:
>  
>
>>Simon Riggs said:
>>    
>>
>>>Following Andrew's concerns, I'd also note that ALTER TABLE requires a
>>>much higher level of privilege to operate than does COPY. That sounds
>>>like it will make things more secure, but all it does is open up the
>>>administrative rights, since full ownership rights must be obtained
>>>merely to load data.
>>>      
>>>
>
>  
>
>>My concern is more about making plain that this is for special operations,
>>not normal operations. Or maybe I have misunderstood the purpose.
>>    
>>
>
>Rephrase that as "full ownership rights must be obtained to load data in
>a way that requires dropping any existing indexes and locking out other
>users of the table".  I don't think the use-case for this will be very
>large for non-owners, or indeed even for owners except during initial
>table creation; and so I don't think the above argument is strong.
>
>			
>  
>

Those restrictions aren't true of Bruce's proposed drop and
delete/truncate recovery modes, are they?

People do crazy things in pursuit of performance. Illustration: a few
months ago I was instrumenting an app (based on MySQL/ISAM) and I
noticed that under load it simply didn't update the inventory properly -
of 1000 orders placed within a few seconds it might reduce inventory by
3 or 4. I reported this and they shrugged their shoulders and said
"well, we'd have to lock the table and that would slow everything down
...".

I just want to be sure we aren't providing a footgun. "Oh, just set
recovery mode to delete. It won't make any difference unless you crash
and you'll run faster."

cheers

andrew




In response to

Responses

pgsql-hackers by date

Next:From: Bruce MomjianDate: 2005-12-30 17:58:15
Subject: Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and
Previous:From: Bruce MomjianDate: 2005-12-30 16:49:59
Subject: Re: [Bizgres-general] WAL bypass for INSERT, UPDATE and

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group