Re: Char vs SmallInt - Mailing list pgsql-general

From Gregory Stark
Subject Re: Char vs SmallInt
Date
Msg-id 87ps2m6tk0.fsf@oxford.xeocode.com
Whole thread Raw
In response to Char vs SmallInt  ("Pg Coder" <pgcoder@gmail.com>)
List pgsql-general
"Pg Coder" <pgcoder@gmail.com> writes:

> Which data type is smaller and will lead to better query performance -
> smallint or char?

smallint is 2 bytes, usually with 2-byte alignment.

If you declare a column as char it means CHAR(1) which in 8.2 is 5-8 bytes (5
bytes if it's an ascii character) and has 4-byte alignment. In 8.3 it's 2-5
bytes (2 bytes if it's an ascii character) and has 1-byte alignment.

If you declare a column as "char" with the quotes then it's a 1-byte integer
with 1-byte alignment. That'll be smaller than smallint.

--
  Gregory Stark
  EnterpriseDB          http://www.enterprisedb.com


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