Difference between CHAR and VARCHAR datatype in SQL Server

Question

What is the Difference between CHAR and VARCHAR datatype in SQL Server

Jaish Mathews · Answer

Here's a tabular comparison of CHAR and VARCHAR datatypes in SQL Server: Feature CHAR VARCHAR Definition Fixed-length string data type Variable-length string data type Storage Always takes the defined length even if fewer characters are stored (padded with spaces) Takes only the required space plus 2 bytes for length storage Performance Faster when handling fixed-size data Slightly slower due to variable-length management Best Used For When all values have the same length (e.g. country codes fixed-size IDs) When values vary in length (e.g. names addresses descriptions) Padding Pads with spaces to match the defined length Does not add padding Storage Size Always consumes the declared size (e.g. CHAR(10) always takes 10 bytes) Consumes actual data length + 2 bytes (e.g. VARCHAR(10) storing Hello takes 5 + 2 = 7 bytes) Maximum Length Up to 8000 characters Up to 8000 characters (or 2GB with VARCHAR(MAX) ) Indexing Efficiency More efficient in indexing due to fixed length Less efficient in indexing due to variable length Use Case Suitable for fixed-size data like codes abbreviations etc. Suitable for variable-length text like names descriptions Would you like a deeper explanation or examples for a particular use case?

Shubham Sidnale · Answer

In SQL Server  both CHAR and VARCHAR are used to store character data but they have key differences: Feature CHAR(n) VARCHAR(n) Definition Fixed-length character data type. Variable-length character data type. Storage Always takes up n bytes even if the actual data is smaller. Takes up only the space required for the data plus 2 bytes for storage overhead. Performance It is faster for fixed-size data because of consistent storage size. More efficient for variable-length data but slightly slower for retrieval due to extra-length calculations. Best Use Case When all values are of a fixed length (e.g. country codes gender status codes). When values vary significantly in length (e.g. names descriptions). Padding Pads extra spaces to match the defined length ( n ). Stores only the actual data without extra spaces.

Muhammad Imran Ansari · Answer

In SQL Server CHAR and VARCHAR are both used to store character string data but they differ in how they handle storage and performance. Here are the key differences: 1. Storage and Length: CHAR: Fixed-length character data type. If you define a CHAR(10)  it will always use 10 bytes of storage regardless of the actual length of the string stored. If the string is shorter than the defined length it is padded with spaces to fill the remaining space. VARCHAR: Variable-length character data type. If you define a VARCHAR(10)  it will only use as much storage as needed to store the actual string up to a maximum of 10 characters. No padding is added so it saves space when storing strings shorter than the maximum length. 2. Performance: CHAR: Can be faster for fixed-length strings because the database engine knows exactly how much space each entry will occupy. However it can waste space if the stored strings are shorter than the defined length. VARCHAR: More space-efficient for variable-length strings but may have a slight performance overhead due to the need to manage variable-length data. Generally preferred when the length of the data varies significantly. 3. Usage Scenarios: CHAR: Best suited for storing data that is consistently the same length such as codes (e.g. ISO country codes state abbreviations) or fixed-length identifiers. VARCHAR: Ideal for storing data where the length can vary significantly such as names addresses or descriptions. 4. Storage Size: CHAR(n): Always uses n bytes of storage. VARCHAR(n): Uses the actual length of the string plus 2 bytes (for length information). Example: -- CHAR example CREATE TABLE ExampleChar ( ID INT Code CHAR(5) ); INSERT INTO ExampleChar (ID Code) VALUES (1 'ABC'); -- 'ABC ' (padded with spaces) -- VARCHAR example CREATE TABLE ExampleVarchar ( ID INT Description VARCHAR(100) ); INSERT INTO ExampleVarchar (ID Description) VALUES (1 'This is a description'); -- No padding