Re: TOAST and TEXT

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Chris Bitmead <chris(at)bitmead(dot)com>, pgsql-hackers(at)postgresql(dot)org
Subject: Re: TOAST and TEXT
Date: 2001-10-13 04:13:32
Message-ID: 200110130413.f9D4DWQ03488@candle.pha.pa.us
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> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > Although the field length is limited to 1GB, is there a row size
> > limit?
>
> Sure. 1Gb per field (hard limit) times 1600 fields (also hard limit).
> In practice less, since TOAST pointers are 20bytes each at present,
> meaning you can't have more than BLCKSZ/20 toasted fields in one row.

I read this as 409GB with 8k pages.

> Whether this has anything to do with real applications is debatable,
> however. I find it hard to visualize a table design that needs several
> hundred columns that *all* need to be GB-sized.

Yes, that just makes my head hurt. Easier to just say "unlimited" and
limited by your computer's memory/disk.

--
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