| From: | "Mikheev, Vadim" <vmikheev(at)SECTORBASE(dot)COM> |
|---|---|
| To: | "'Bruce Momjian'" <pgman(at)candle(dot)pha(dot)pa(dot)us>, Hiroshi Inoue <Inoue(at)tpf(dot)co(dot)jp> |
| Cc: | Don Baccus <dhogaza(at)pacifier(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "'Zeugswetter Andreas SB'" <ZeugswetterA(at)wien(dot)spardat(dot)at>, The Hermit Hacker <scrappy(at)hub(dot)org>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | RE: Plans for solving the VACUUM problem |
| Date: | 2001-05-25 16:37:16 |
| Message-ID: | 3705826352029646A3E91C53F7189E32016656@sectorbase2.sectorbase.com |
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| Lists: | pgsql-hackers |
> Do we want to head for an overwriting storage manager?
>
> Not sure.
>
> Advantages: UPDATE has easy space reuse because usually done
> in-place, no index change on UPDATE unless key is changed.
>
> Disadvantages: Old records have to be stored somewhere for MVCC use.
> Could limit transaction size.
Really? Why is it assumed that we *must* limit size of rollback segments?
We can let them grow without bounds, as we do now keeping old records in
datafiles and letting them eat all of disk space.
> UNDO disadvantages are:
>
> Limit size of transactions to log storage size.
Don't be kidding - in any system transactions size is limitted
by available storage. So we should tell that more disk space
is required for UNDO. From my POV, putting $100 to buy 30Gb
disk is not big deal, keeping in mind that PGSQL requires
$ZERO to be used.
Vadim
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| Next Message | Mikheev, Vadim | 2001-05-25 17:05:31 | RE: Plans for solving the VACUUM problem |
| Previous Message | Teodor Sigaev | 2001-05-25 16:29:21 | Re: GiST index on data types that require compression |