Симонов ДенисПроизводительность при работе с BLOB это уже второй вопрос.Это делает его использование неприемлимым. Плюс отсутствие индексов по ним.
А вот как хочется:
http://www.postgresql.org/docs/9.3/static/datatype-character.html The storage requirement for a short string (up to 126 bytes) is 1 byte plus the actual string, which
includes the space padding in the case of character. Longer strings have 4 bytes of overhead instead
of 1. Long strings are compressed by the system automatically, so the physical requirement on disk
might be less. Very long values are also stored in background tables so that they do not interfere with
rapid access to shorter column values. In any case, the longest possible character string that can be
stored is about 1 GB. (The maximum value that will be allowed for n in the data type declaration
is less than that. It wouldn’t be useful to change this because with multibyte character encodings
the number of characters and bytes can be quite different. If you desire to store long strings with no
specific upper limit, use text or character varying without a length specifier, rather than making
up an arbitrary length limit.)
Tip:
There is no performance difference among these three types, apart from increased storage
space when using the blank-padded type, and a few extra CPU cycles to check the length when
storing into a length-constrained column. While character(n) has performance advantages in
some other database systems, there is no such advantage in PostgreSQL; in fact character(n)
is usually the slowest of the three because of its additional storage costs.
In most situations text
or character varying should be used instead .
