Re: [HACKERS] [GENERAL] Large databases, performance
От | Martijn van Oosterhout |
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Тема | Re: [HACKERS] [GENERAL] Large databases, performance |
Дата | |
Msg-id | 20021008225111.GA8663@svana.org обсуждение исходный текст |
Ответ на | Re: [HACKERS] [GENERAL] Large databases, performance ("Zeugswetter Andreas SB SD" <ZeugswetterA@spardat.at>) |
Список | pgsql-performance |
On Mon, Oct 07, 2002 at 05:42:12PM +0200, Zeugswetter Andreas SB SD wrote: > > Hackers, do you think it's possible to hack together a quick and dirty > > patch, so that string length is represented by one byte? IOW can a > > database be built that doesn't contain any char/varchar/text value > > longer than 255 characters in the catalog? > > Since he is only using fixchar how about doing a fixchar implemetation, that > does not store length at all ? It is the same for every row anyways ! Remember that in Unicode, 1 char != 1 byte. In fact, any encoding that's not Latin will have a problem. I guess you could put a warning on it: not for use for asian character sets. So what do you do if someone tries to insert such a string anyway? Perhaps a better approach is to vary the number of bytes used for the length. So one byte for lengths < 64, two bytes for lengths < 16384. Unfortunatly, two bits in the length are already used (IIRC) for other things making it a bit more tricky. -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > There are 10 kinds of people in the world, those that can do binary > arithmetic and those that can't.
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