Re: [NOVICE] varchar vs varchar(n)
| От | Tom Lane |
|---|---|
| Тема | Re: [NOVICE] varchar vs varchar(n) |
| Дата | |
| Msg-id | 21800.1510515292@sss.pgh.pa.us обсуждение исходный текст |
| Ответ на | [NOVICE] varchar vs varchar(n) (john snow <ofbizfanster@gmail.com>) |
| Ответы |
Re: [NOVICE] varchar vs varchar(n)
|
| Список | pgsql-novice |
john snow <ofbizfanster@gmail.com> writes:
> do postgresql developers just use varchar instead of specifying a limit n
> when dealing with string types? if so, are there any gotcha's i should be
> aware of?
Generally speaking, I would only use varchar(n) when there is a clear
reason traceable to application requirements why there has to be a
limit, and why the limit should be n and not some other number.
Otherwise you're just creating issues for yourself. The habit of
inventing arbitrary limits on text column width is just a hangover
from punched-card days.
Actually, Postgres people tend to use "text" rather than unconstrained
"varchar". In principle those two types behave equivalently; but the
system has to jump through some extra hoops to work with varchar, and
every so often you'll run into a case where "varchar" is not optimized
as well as "text".
regards, tom lane
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