October 23rd, 2008

GRAPHIC(length) Data

Posted by admin in F. Data Types

In DB2 the GRAPHIC data type can have up to 127 characters of 16-bit Double Byte Character Set data. With DBCS, each 2 bytes of data represents a graphic character. This data type is rarely used. Consult your RDBMS systems manual for further details.

 

Example:    COL1 GRAPHIC(50)

COL1 has 100 bytes of 50 double byte characters.

October 22nd, 2008

Binary Large OBject (BLOB) Data, Part 2 of 2

Posted by admin in F. Data Types

Binary Large OBject (BLOB) data is coded by the RDBMS vendors as follows:

October 21st, 2008

Binary Large OBject (BLOB) Data, Part 1 of 2

Posted by admin in F. Data Types

Binary Large Object Data is represented by the following:

> Unlike a CLOB, which stores a long character string, a BLOB stores a long bit string. These two data types are not interchangable.

> BLOBs are used to store large multimedia data such as digitized pictures, medical photos, 3D graphics, videos, audios, audio/visual movies, data recordings, etc.

> BLOBs can be either fixed in length or variable in length.

 
> A BLOB can not be used as a PRIMARY KEY, FOREIGN KEY, or UNIQUE predicate.
    A BLOB can not be used in any comparison other than equal or not equal.
    You also can not use BLOBs with DISTINCT, GROUP BY, or ORDER BY.

> RDBMS systems don’t try to interpret BLOBs, that is left to you and your application.

> SQL:1999 introduced BLOBs as a data type.

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