Blob type
The Cassandra blob data type represents a constant hexadecimal number defined as 0[xX](hex)+ where hex is an hexadecimal character, such as [0-9a-fA-F]. For example, 0xcafe. The maximum theoretical size for a blob is 2GB. The practical limit on blob size, however, is less than 1 MB, ideally even smaller. A blob type is suitable for storing a small image or short string.
Blob conversion functions
These functions convert the native types into binary data (blob):
- typeAsBlob(type)
- blobAsType
For every native, nonblob type supported by CQL, the typeAsBlob function takes a argument of type type and returns it as a blob. Conversely, the blobAsType function takes a 64-bit blob argument and converts it to a bigint value.
This example shows how to use bitintAsBlob:
CREATE TABLE bios ( user_name varchar PRIMARY KEY,
bio blob
);
INSERT INTO bios (user_name, bio) VALUES ('fred', bigintAsBlob(3));
This example shows how to use blobAsBigInt.
ALTER TABLE bios ADD id bigint;
INSERT INTO bios (user_name, id) VALUES ('fred', blobAsBigint(0x0000000000000003));