Re: More thoughts about FE/BE protocol

From: Jan Wieck <JanWieck(at)Yahoo(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Hannu Krosing <hannu(at)tm(dot)ee>, Peter Galbavy <peter(dot)galbavy(at)knowtion(dot)net>, pgsql-hackers(at)postgreSQL(dot)org, pgsql-interfaces(at)postgreSQL(dot)org
Subject: Re: More thoughts about FE/BE protocol
Date: 2003-04-10 20:28:46
Message-ID: 3E95D3FE.5DE02EA6@Yahoo.com
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Tom Lane wrote:
>
> Hannu Krosing <hannu(at)tm(dot)ee> writes:
> > Tom Lane kirjutas N, 10.04.2003 kell 16:57:
> >> See my response to ljb --- I think that in practice people assemble each
> >> message before sending anyway.
>
> > I just tested it by running "select *" on 68M records (6.5 GB data)
> > table and you seem to be wrong - while psql shows nothing, its size
> > starts rapidly growing (I ^C it at ~500M) , while backend stays at
> > stable 32M, which indicates that postgres starts to push data out as
> > fast as it can get it.
>
> Sure. "Message" here is at the granularity of one data row, not an
> entire query result.

Could even be smaller since TOASTed items don't get loaded at the row
level but rather one after another. So a 68M row consisting of 4 17M
fields doesn't require 68M of memory to be sent to the client.

Jan

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