I would like to know how to use these datatypes.
Each table in our database will have arabic as well as english data stored in it.
Is it ok to use VARCHAR2 only or do i have to declare the arabic columns as NVARCHAR2.
Will there be a change in the way the tables are queried?
NCHAR: - A standard Oracle datatype. The NCHAR datatype specifies a fixed-width national character set character string, and can have a maximum column size up to 2000 bytes.
A standard Oracle datatype. The NVARCHAR2 datatype specifies a variable-length NCHAR string. NVARCHAR2 width specifications refer to the number of characters if the national character set is fixed-width, and to the number of bytes if the national character set is varying-width. The maximum column size allowed is 4000 bytes.
An Oracle Corporation datatype. Specifically, it is a variable-length, alpha-numeric string with a maximum length of 4000 characters. If data entered for a column of type VARCHAR2 is less than 4000 no spaces will be padded; the data is stored with a length as entered. If data entered is more than 4000, an error occurs.
From the above definitions of the different type of datatypes comparison, i would suggest u to use the NVARCHAR2 datatype if u r getting in the defined chacterset (arabic) data in that column ...