Difference between BYTE and CHAR in column datatypes

Question

In Oracle  what is the difference between    CREATE TABLE CLIENT    NAME VARCHAR2 11 BYTE    ID CLIENT NUMBER     and  CREATE TABLE CLIENT    NAME VARCHAR2 11 CHAR   -- or even VARCHAR2 11   ID CLIENT NUMBER

User · Accepted Answer

Let us assume the database character set is UTF-8, which is the recommended setting in recent versions of Oracle. In this case, some characters take more than 1 byte to store in the database.

If you define the field as VARCHAR2(11 BYTE), Oracle can use up to 11 bytes for storage, but you may not actually be able to store 11 characters in the field, because some of them take more than one byte to store, e.g. non-English characters.

By defining the field as VARCHAR2(11 CHAR) you tell Oracle it can use enough space to store 11 characters, no matter how many bytes it takes to store each one. A single character may require up to 4 bytes.

User · Answer

One has exactly space for 11 bytes  the other for exactly 11 characters  Some charsets such as Unicode variants may use more than one byte per char  therefore the 11 byte field might have space for less than 11 chars depending on the encoding   See also http   www joelonsoftware com articles Unicode html

User · Answer

One has exactly space for 11 bytes  the other for exactly 11 characters  Some charsets such as Unicode variants may use more than one byte per char  therefore the 11 byte field might have space for less than 11 chars depending on the encoding   See also http   www joelonsoftware com articles Unicode html

User · Answer

One has exactly space for 11 bytes  the other for exactly 11 characters  Some charsets such as Unicode variants may use more than one byte per char  therefore the 11 byte field might have space for less than 11 chars depending on the encoding   See also http   www joelonsoftware com articles Unicode html

User · Answer

One has exactly space for 11 bytes  the other for exactly 11 characters  Some charsets such as Unicode variants may use more than one byte per char  therefore the 11 byte field might have space for less than 11 chars depending on the encoding   See also http   www joelonsoftware com articles Unicode html

User · Answer

One has exactly space for 11 bytes  the other for exactly 11 characters  Some charsets such as Unicode variants may use more than one byte per char  therefore the 11 byte field might have space for less than 11 chars depending on the encoding   See also http   www joelonsoftware com articles Unicode html

User · Answer

One has exactly space for 11 bytes  the other for exactly 11 characters  Some charsets such as Unicode variants may use more than one byte per char  therefore the 11 byte field might have space for less than 11 chars depending on the encoding   See also http   www joelonsoftware com articles Unicode html

User · Answer

One has exactly space for 11 bytes  the other for exactly 11 characters  Some charsets such as Unicode variants may use more than one byte per char  therefore the 11 byte field might have space for less than 11 chars depending on the encoding   See also http   www joelonsoftware com articles Unicode html

User · Answer

One has exactly space for 11 bytes  the other for exactly 11 characters  Some charsets such as Unicode variants may use more than one byte per char  therefore the 11 byte field might have space for less than 11 chars depending on the encoding   See also http   www joelonsoftware com articles Unicode html

User · Answer

Depending on the system configuration  size of CHAR mesured in BYTES can vary  In your examples    Limits field to 11 BYTE Limits field to 11 CHARacters    Conclusion  1 CHAR is not equal to 1 BYTE

User · Answer

Depending on the system configuration  size of CHAR mesured in BYTES can vary  In your examples    Limits field to 11 BYTE Limits field to 11 CHARacters    Conclusion  1 CHAR is not equal to 1 BYTE

User · Answer

Depending on the system configuration  size of CHAR mesured in BYTES can vary  In your examples    Limits field to 11 BYTE Limits field to 11 CHARacters    Conclusion  1 CHAR is not equal to 1 BYTE

User · Answer

Depending on the system configuration  size of CHAR mesured in BYTES can vary  In your examples    Limits field to 11 BYTE Limits field to 11 CHARacters    Conclusion  1 CHAR is not equal to 1 BYTE

User · Answer

Depending on the system configuration  size of CHAR mesured in BYTES can vary  In your examples    Limits field to 11 BYTE Limits field to 11 CHARacters    Conclusion  1 CHAR is not equal to 1 BYTE

User · Answer

Depending on the system configuration  size of CHAR mesured in BYTES can vary  In your examples    Limits field to 11 BYTE Limits field to 11 CHARacters    Conclusion  1 CHAR is not equal to 1 BYTE

User · Answer

Depending on the system configuration  size of CHAR mesured in BYTES can vary  In your examples    Limits field to 11 BYTE Limits field to 11 CHARacters    Conclusion  1 CHAR is not equal to 1 BYTE

User · Answer

Depending on the system configuration  size of CHAR mesured in BYTES can vary  In your examples    Limits field to 11 BYTE Limits field to 11 CHARacters    Conclusion  1 CHAR is not equal to 1 BYTE

User · Answer

I am not sure since I am not an Oracle user, but I assume that the difference lies when you use multi-byte character sets such as Unicode (UTF-16/32). In this case, 11 Bytes could account for less than 11 characters.