Convert BLOB data to a character string in order to store the information on servers that do not typically support the data type.
Many database servers support character data but not BLOB data. You can store BLOB data on these servers by converting it to a character string format before sending it. When reading data back from such servers, you must convert the data from the character string format back to the original Sybase CEP BLOB format.
Sybase CEP Server uses base64 encoding and decoding to convert a BLOB to a character string and vice versa.
In base64 encoding, every 3 bytes of BLOB data is converted to 4 bytes of character string data. This means that the output requires 4/3 as many bytes as the input. If the external database server character data type has a limit of N bytes per character string, then you can only store 3/4 * N bytes in the server. For example, if the external database server has a limit of 2000 bytes per character string, then the longest BLOB it can store is 1500 bytes, which is expanded to 2000 bytes after base64 encoding. The exact limit may be slightly less than 3/4 * N due to various factors, such as the input not being an exact multiple of 3 bytes.
The DBDriverCharBufferSize limits the maximum size of data that you can write to (or read from) remote database servers.