Binary Data Types

Updated on 2024-12-19 GMT+08:00

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Table 1 lists the binary data types that can be used in GaussDB(DWS).

**Table 1** Binary Data Types
Name	Description	Storage Space
BLOB	Binary large object. Currently, BLOB only supports the following external access interfaces: DBMS_LOB.GETLENGTH DBMS_LOB.READ DBMS_LOB.WRITE DBMS_LOB.WRITEAPPEND DBMS_LOB.COPY DBMS_LOB.ERASE For details about the interfaces, see DBMS_LOB. NOTE: Column storage cannot be used for the BLOB type.	The maximum size is 10,7373,3621 bytes (1 GB - 8203 bytes).
RAW	Variable-length hexadecimal string NOTE: Column storage cannot be used for the raw type.	4 bytes plus the actual hexadecimal string. The maximum size is 10,7373,3621 bytes (1 GB - 8203 bytes).
BYTEA	Variable-length binary string	4 bytes plus the actual binary string. The maximum size is 10,7373,3621 bytes (1 GB - 8203 bytes).

NOTE:

In addition to the size limitation on each column, the total size of each tuple is 8203 bytes less than 1 GB.

Example

Create a table:

    
       CREATE TABLE blob_type_t1 
(
    BT_COL1 INTEGER,
    BT_COL2 BLOB,
    BT_COL3 RAW,
    BT_COL4 BYTEA
) DISTRIBUTE BY REPLICATION;

Insert data:

    
       INSERT INTO blob_type_t1 VALUES(10,empty_blob(),HEXTORAW('DEADBEEF'),E'\\xDEADBEEF');

Query data in the table:

    
       SELECT * FROM blob_type_t1;
 bt_col1 | bt_col2 | bt_col3  |  bt_col4   
---------+---------+----------+------------
      10 |         | DEADBEEF | \xdeadbeef
(1 row)