How many bytes does Oracle use when storing a single character?

Question

I tried to look here:

http://download.oracle.com/docs/cd/B19306_01/server.102/b14220/datatype.htm#i3253

And I understand that I have to provide string length for the column, I'm just not able to find out how many bytes oracle uses when storing a character. My limit is 500 characters, so if its 1 byte / character, I can create the column with 500, if its 2 byte / character then 1000, etc.

Anyone have a link to the documentation or know for certain?

In case it matters, the SQL is being called from PHP, so these are PHP strings I'm inserting into the database. Thanks.

Answer 1

A single CHAR will take 1 byte.

Try here:

http://ss64.com/ora/syntax-datatypes.html

Answer 2

Hi Mr-sk,

the number of bytes needed to store a character will depend upon the character set. If you want to store 500 characters and don't know the character set of the target database you should create the column (or variable) as a VARCHAR2(500 CHAR) or CHAR(500 CHAR).

Answer 3

A plain CHAR is not necessarily one byte, depending on the setting of NLS_LENGTH_SEMANTICS.

See Oracle's SQL Language Reference as a starting point. If you need to dig deeper, have a look at Oracle's Globalization Support Guide.