Re: [SQL] how to change the type
От | Stephan Szabo |
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Тема | Re: [SQL] how to change the type |
Дата | |
Msg-id | 20011206183802.E30420-100000@megazone23.bigpanda.com обсуждение исходный текст |
Ответ на | Re: [SQL] how to change the type ("Christopher Kings-Lynne" <chriskl@familyhealth.com.au>) |
Ответы |
Re: [SQL] how to change the type
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Список | pgsql-hackers |
On Fri, 7 Dec 2001, Christopher Kings-Lynne wrote: > OK, I'm kind of interested now in how the variable length attributes are > actually stored on disk, that you are able to increase them, but not > decrease? > > I would have thought the other way around? IIRC, the values are stored as length + data. I think char() might do wierd things (I don't know if the trailing spaces are stored), but varchar() and text should be expandable because anything that could have fit before should still fit and look the same. Going down is problematic, because if you have a varchar(5) field where one value is say 'abcd' and you make it varchar(3) what happens?
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