INDEX on RAW data type

728256

Hi,

I read this from a web site. Please let me know fi thsi is correct.

The raw datatype is used to store binary data or binary strings. The maximum size for a raw in a table is 2000 bytes. Within a PL/SQL piece of code, the maximum size is 32767 bytes. The raw datatype is similar to the varchar2. However, Oracle does not interprete the data stored within a raw when applying character set conversion.

If the above is correct them, What happens when I create Index on this column. We have table with Primary key on Raw column. Is this acceptable or a wrong way of creating the table.

Please explain in detail if possible or direct me to a book or URL where I can find the information.

Thanking you
Rocky

558383

In general, RAW columns can be indexed but LONG RAW cannot.

See SQL Reference CREATE INDEX section http://download.oracle.com/docs/cd/B28359_01/server.111/b28286/statements_5011.htm#i2182635

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Restriction on Index Columns

You cannot create an index on columns or attributes whose type is user-defined, LONG, LONG RAW, LOB, or REF, except that Oracle Database supports an index on REF type columns or attributes that have been defined with a SCOPE clause.
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Documentation on SQL data types can be found in SQL Reference http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/sql_elements001.htm#i54330.
Document on PL/SQL data types can be found in PL/SQL User's Guide and Reference: http://download.oracle.com/docs/cd/B19306_01/appdev.102/b14261/datatypes.htm#i10924

Please post your 4 digits Oracle version.

Edited by: P. Forstmann on 3 févr. 2010 23:16