Binary Types

Table 1 lists the binary types supported by GaussDB.

**Table 1** Binary types
Name	Description	Storage Space
BLOB	Binary large object (BLOB). Currently, BLOB only supports the following external access APIs: DBE_LOB.GET_LENGTH DBE_LOB.READ DBE_LOB.WRITE DBE_LOB.WRITE_APPEND DBE_LOB.COPY DBE_LOB.ERASE For details about the APIs, see DBE_LOB.	For Astore, the maximum size is 32 TB minus 1 byte. However, the size of the column description header and the size of the tuple (less than 32 TB minus 1 byte) where the column is located must also be considered. Therefore, the maximum size of the BLOB type may be less than 32 TB minus 1 byte. For Ustore, the maximum size is 1 GB minus 1 byte. However, the size of the column description header and the size of the tuple (less than 1 GB minus 1 byte) where the column is located must also be considered. Therefore, the maximum size of the BLOB type may be less than 1 GB minus 1 byte.
RAW	Variable-length hexadecimal string.	4 bytes plus the actual binary string. The maximum size is 1 GB minus 1 byte. However, the size of the column description header and the size of the tuple (less than 1 GB minus 1 byte) where the column is located must also be considered. Therefore, the maximum size of this type may be less than 1 GB minus 1 byte.
BYTEA	Variable-length binary string.	4 bytes plus the actual binary string. The maximum size is 1 GB minus 1 byte. However, the size of the column description header and the size of the tuple (less than 1 GB minus 1 byte) where the column is located must also be considered. Therefore, the maximum size of this type may be less than 1 GB minus 1 byte.

In addition to the size limitation on each column, the total size of each tuple is 1,073,741,823 bytes (1 GB minus 1 bytes).
RAW(n), where n indicates the recommended byte length and is not used to verify the byte length of the input raw type.
GaussDB supports a maximum of 1 GB data transfer, and the maximum size of the result string returned by the function is 1 GB.

Example:

   
        -- Create a table.
gaussdb=# CREATE TABLE blob_type_t1 
(
    BT_COL1 INTEGER,
    BT_COL2 BLOB,
    BT_COL3 RAW,
    BT_COL4 BYTEA
) DISTRIBUTE BY REPLICATION;

-- Insert data.
gaussdb=# INSERT INTO blob_type_t1 VALUES(10,empty_blob(),
HEXTORAW('DEADBEEF'),E'\\xDEADBEEF');

-- Query data in the table.
gaussdb=# SELECT * FROM blob_type_t1;
 bt_col1 | bt_col2 | bt_col3  |  bt_col4   
---------+---------+----------+------------
      10 |         | DEADBEEF | \xdeadbeef
(1 row)

-- Drop the table.
gaussdb=# DROP TABLE blob_type_t1;