From: Emi Lu <emilu@encs.concordia.ca>
To: Andrew Dunstan <andrew@dunslane.net>
Cc: pgsql-performance@postgresql.org <pgsql-performance@postgresql.org>
Subject: Re: char(N), varchar(N), varchar, text
Date: Wed, 08 Oct 2014 10:42:55 -0400
Message-ID: <54354D6F.1080002@encs.concordia.ca> (raw)
In-Reply-To: <54354A73.6030607@dunslane.net>
References: <543548B4.4060700@encs.concordia.ca>
<54354A73.6030607@dunslane.net>
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>
>>
>> For performance point of view, are there big differences between:
>> char(N), varchar(N), varchar, text?
>>
>> Some comments from google shows:
>> No difference, under the hood it's all varlena. Check this article
>> from Depesz:
>> http://www.depesz.com/index.php/2010/03/02/charx-vs-varcharx-vs-varchar-vs-text/
>> A couple of highlights:
>>
>> To sum it all up:
>>
>> * char(n) – takes too much space when dealing with values
>> shorter than n, and can lead to subtle errors because of
>> adding trailing spaces, plus it is problematic to change the
>> limit
>> * varchar(n) – it's problematic to change the limit in live
>> environment
>> * varchar – just like text
>> * text – for me a winner – over (n) data types because it lacks
>> their problems, and over varchar – because it has distinct name
>>
>> So, can I assume no big performance differences?
>> Thanks alot!
>> Emi
>>
>
>
> Why do you need to ask if you already have the answer? Depesz is right.
Good to hear this. Well, sorry I saw the time is:/2010/03 (might changes
for diff/newer versions).
Thank you for the confirmation.
Emi
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To: pgsql-performance@postgresql.org
Cc: emilu@encs.concordia.ca, andrew@dunslane.net
Subject: Re: char(N), varchar(N), varchar, text
In-Reply-To: <54354D6F.1080002@encs.concordia.ca>
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