Using Large Character or Binary Data Types

By default, .NET byte[] maps to RAW(2000) and .NET string maps to NVARCHAR(2000). But if your application deals with data that larger than 2000 bytes, you can use the Column or the MaxLength data annotations or the associated fluent API to create BLOB and CLOB columns in the database, respectively.

// This annotation will force a BLOB column to be created.
[Column("BLOB_COLUMN", TypeName = "BLOB")]
public byte[] BYTE_TYPE { get; set; }
// This annotations will force a NCLOB column to be created.
public string NCLOB_TYPE { get; set; }

Without these annotations, you may hit errors, such as “ORA-01460: unimplemented or unreasonable conversion requested” or “ORA-12899: value too large for column” when modifying the data.