RE: PostgreSQL and mySQL database size question

Bruce,

I have your book right in front of me... do you have that information in the
book? If not, I will take a look at the FAQ. As for mySQL, here are the
storage requirements:

Storage requirements for numeric types

Column type Storage required
TINYINT 1 byte
SMALLINT 2 bytes
MEDIUMINT 3 bytes
INT 4 bytes
INTEGER 4 bytes
BIGINT 8 bytes
FLOAT(X) 4 if X <= 24 or 8 if 25 <= X <= 53
FLOAT 4 bytes
DOUBLE 8 bytes
DOUBLE PRECISION 8 bytes
REAL 8 bytes
DECIMAL(M,D) M+2 bytes if D > 0, M+1 bytes if D = 0 (D+2, if M < D)
NUMERIC(M,D) M+2 bytes if D > 0, M+1 bytes if D = 0 (D+2, if M < D)

Storage requirements for date and time types

Column type Storage required
DATE 3 bytes
DATETIME 8 bytes
TIMESTAMP 4 bytes
TIME 3 bytes
YEAR 1 byte

Storage requirements for string types

Column type Storage required

CHAR(M) M bytes, 1 <= M <= 255
VARCHAR(M) L+1 bytes, where L <= M and 1 <= M <= 255
TINYBLOB,
TINYTEXT L+1 bytes, where L < 2^8
BLOB, TEXT L+2 bytes, where L < 2^16
MEDIUMBLOB,
MEDIUMTEXT L+3 bytes, where L < 2^24
LONGBLOB,
LONGTEXT L+4 bytes, where L < 2^32
ENUM('value1','value2',...) 1 or 2 bytes, depending on the number of
enumeration values (65535 values maximum)
SET('value1','value2',...) 1, 2, 3, 4 or 8 bytes, depending on the number of
set members (64 members maximum)

Fred

-----Original Message-----
From: Bruce Momjian [mailto:pgman(at)candle(dot)pha(dot)pa(dot)us]
Sent: Friday, April 27, 2001 1:48 PM
To: ingham(at)erols(dot)com
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: [GENERAL] PostgreSQL and mySQL database size question

Did you see the FAQ items on estimating database sizes? Does MySQL have
less overhead per row?