PostgreSQL - Numeric Types

Please note, that unlike MySQL / MariaDB, PostgreSQL does not support adding the UNSIGNED flag to any of these types.

Integer Types

SMALLINT

• -32768 to 32767
• Storage Size: 2 bytes

INTEGER / INT

• -2147483648 to 2147483647
• Storage Size: 4 bytes

BIGINT

• -9223372036854775808 to 9223372036854775807
• Storage Size: 4 bytes

Auto-Incrementing Integer Types

SMALLSERIAL

• 1 to 32767
• Storage Size: 2 bytes

SERIAL

• 1 to 2147483647
• Storage Size: 4 bytes

BIGSERIAL

• 1 to 9223372036854775807
• Storage Size: 8 bytes

Decimal Types

The following types are for when you need to store a number with a decimal point.

DECIMAL / NUMERIC

• up to 131072 digits before the decimal point
• up to 16383 digits after the decimal point
• Exact precision (e.g. not like how a float works).
• Storage Size: variable based on specified scale/precision.
• E.g. DECIMAL(3,2) (will be able to store 1.23 but not 12.3)
• E.g. NUMERIC(3,2) (will be able to store 1.23 but not 12.3)

DECIMAL and NUMERIC are synonyms. E.g. PostgreSQL works exactly the same under the hood, and just supports having two names for the same thing. More info

REAL

• Variable precision using 6 decimal digits (e.g. like how a float works). E.g. can store 0.000000000000000123456 or 123456000000000000000 but not 1234567.
• Storage Size: 4 bytes

DOUBLE PRECISION

• Exactly like REAL except uses 8 bytes of storage in order to allow 15 decimal digits of precision.
• Storage Size: 8 bytes

References

• PostgreSQL.org - Numeric Types