Integer vs Bigint in PostgreSQL: Key Differences and Usage

In PostgreSQL, integer is a 4-byte data type that stores whole numbers from -2,147,483,648 to 2,147,483,647, while bigint is an 8-byte data type with a much larger range from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807. Use integer for typical counts and IDs, and bigint when you expect very large numbers beyond the integer range.

Quick Comparison

Here is a quick side-by-side comparison of integer and bigint in PostgreSQL.

Feature	integer	bigint
Storage Size	4 bytes	8 bytes
Range	-2,147,483,648 to 2,147,483,647	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
Typical Use Case	Standard counts, IDs, small numeric values	Very large counts, IDs, or numeric values
Performance	Faster due to smaller size	Slightly slower due to larger size
Default for SERIAL	Yes (SERIAL is integer auto-increment)	No (use BIGSERIAL for bigint auto-increment)

Key Differences

The main difference between integer and bigint in PostgreSQL is their size and range. integer uses 4 bytes of storage and can hold values roughly between -2 billion and +2 billion. This is sufficient for most applications like user IDs, counts, or small numeric values.

On the other hand, bigint uses 8 bytes and supports a much larger range, from about -9 quintillion to +9 quintillion. This is useful when you expect numbers to exceed the integer limit, such as very large counters or IDs in massive datasets.

Because bigint uses more storage, it can be slightly slower in processing and uses more disk space. Therefore, choosing between them depends on your data size needs and performance considerations.

Code Comparison

Here is how you declare and insert values using integer in PostgreSQL.

sql

CREATE TABLE example_integer (
  id SERIAL PRIMARY KEY,
  count_value INTEGER
);

INSERT INTO example_integer (count_value) VALUES (123456);

SELECT * FROM example_integer;

Output

 id | count_value 
----+-------------
  1 |      123456
(1 row)

Bigint Equivalent

Here is the equivalent table and insert using bigint in PostgreSQL.

sql

CREATE TABLE example_bigint (
  id BIGSERIAL PRIMARY KEY,
  count_value BIGINT
);

INSERT INTO example_bigint (count_value) VALUES (1234567890123);

SELECT * FROM example_bigint;

Output

 id |  count_value   
----+----------------
  1 | 1234567890123
(1 row)

When to Use Which

Choose integer when your numbers fit comfortably within the ±2 billion range, such as typical user IDs, small counters, or flags. It uses less storage and offers better performance.

Choose bigint when you expect very large numbers that exceed the integer range, like global unique IDs, large financial figures, or huge counters. Although it uses more space, it prevents overflow errors.

Key Takeaways

Use integer for most common numeric needs with values within ±2 billion.

Use bigint for very large numbers beyond the integer range to avoid overflow.

integer uses 4 bytes, bigint uses 8 bytes of storage.

bigint can be slightly slower and uses more disk space than integer.

Pick the type based on your data size needs to balance performance and capacity.