Storing Binary Data in varchar2 fields

We have a need to define a table that will store a variable amount of binary data in a column. The length will be less than 4000 bytes.

I have been told that there is overhead involved when using blob fields. This is an OLTP app with heavy traffic (select, update). Performance in updating and selecting this data is critical. This binary data will never be part of our selection criteria, but we will always be returning it in our queries and we will be updating it.

Since the length of our data is small, we were hoping to avoid that overhead by making the column varchar2. However, I have read some information that indicates that I can not store binary data in a varchar2 field because Oracle will perform translations.

I have also read that the raw datatype is merely varchar2 without any translation, which sounds like what I want. However, the docs indicate that blobs should be used as of 8i (we are using 9.2).

My questions are:

• Is there really a performance hit when using blobs?
• Can I safely use varchar2?

Thanks for any help. Received on Thu Jun 12 2003 - 14:32:51 CDT