Re: How can fixed and variable width columns perform similarly?

Поиск
Список
Период
Сортировка
От Siddharth Anand
Тема Re: How can fixed and variable width columns perform similarly?
Дата
Msg-id 50516.209.51.183.100.1177690744.squirrel@mailbox.etsy.com
обсуждение исходный текст
Ответ на Re: How can fixed and variable width columns perform similarly?  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: How can fixed and variable width columns perform similarly?
Список pgsql-performance
Hi Tom,
My question wasn't phrased clearly. Oracle exhibits a performance
degradation for very large-sized fields (CLOB types that I equate to
PostGres' text type) when compared with the performance of field types
like varchar that handle a max character limit of a few thousand bytes in
Oracle.

It sounds like PostGres doesn't exhibit this same difference. I wanted to
understand how this could be and whether there was a trade-off.

Cheers!
Sid
> "Siddharth Anand" <sid@etsy.com> writes:
>> How can a field that doesn't have a limit like "text" perform similarly
>> to
>> char varying(128), for example? At some point, we need to write data to
>> disk. The more data that needs to be written, the longer the disk write
>> will take, especially when it requires finding free sectors to write to.
>
> What's your point?  If you're not going to put more than 128 characters
> in the field, there's no difference in the amount of data involved.
>
>             regards, tom lane
>
> ---------------------------(end of broadcast)---------------------------
> TIP 2: Don't 'kill -9' the postmaster
>



В списке pgsql-performance по дате отправления:

Предыдущее
От: "Dave Dutcher"
Дата:
Сообщение: Re: How can fixed and variable width columns perform similarly?
Следующее
От: Tom Lane
Дата:
Сообщение: Re: How can fixed and variable width columns perform similarly?