Question

I want to store a short array of 64 bytes in Oracle database (a password hash). I thought char(64 byte) is what I need, but it seems like it doesn’t work. In Microsoft SQL, I use binary and varbinary types. What type do I need to use in Oracle?

Every example I’ve found uses blob to store binary data, but I suppose blob is intended only for large objects, not for fixed size short arrays.

When updating the data, is the code like this appropriate:

byte[] passwordHash = GenerateHash();

using (OracleCommand updateHash = new OracleCommand("update A set passwordHash = :hash where EntryId = :id", oracleConnection))
{
    updateHash.Parameters.Add(":hash", passwordHash);
    updateHash.Parameters.Add(":id", entryId);

    if (updateHash.ExecuteNonQuery() != 1)
    {
        // ...
    }
}

or am I missing something and byte array parameters cannot be added like this?

Answer 1

In addition to blob, Oracle also has the RAW datatype,

RAW is a variable-length datatype like
VARCHAR2

— Oracle 10g Release 2 Datatypes

RAW can be set up to a max size of 2000 bytes, with LONG RAW having a max size of 2GB.

However:

Oracle strongly recommends that you
convert LONG RAW columns to binary
LOB (BLOB) columns. LOB columns are
subject to far fewer restrictions than
LONG columns.