FAQ

Q1: What are Databend's primary objects, hierarchy, and associated privileges?

The diagram illustrates the hierarchical structure of Databend objects across two levels. Fine-grained privileges and ownership are designed for each type of object, providing flexibility. For more information, see Access Control.

Q2: How do I create a table in Databend?

Use the CREATE TABLE command to create a table in Databend:

Example:

CREATE TABLE example (
-- Except for DECIMAL, no need to specify field length.
  c1 INT,
  c2 VARCHAR,
  c3 DATETIME,
  c4 DECIMAL(20, 2),
  c5 BITMAP,
  c6 TUPLE (FLOAT, FLOAT)
);

Q3: What are the data type mappings across Databend, MySQL, and Oracle?

This table provides an outline of the mapping of data types between Databend, MySQL, and Oracle.

Databend	MySQL	Oracle
TINYINT	TINYINT	NUMBER(3,0)
SMALLINT	SMALLINT	NUMBER(5,0)
INT	INT	NUMBER(10,0)
BIGINT	BIGINT	NUMBER(19,0)
FLOAT	FLOAT	FLOAT
DOUBLE	DOUBLE	FLOAT(24)
DECIMAL	DECIMAL	NUMBER
DATE	DATE	DATE
TIMESTAMP	TIMESTAMP	NUMBER
DATETIME	DATETIME	DATE
YEAR	INT	NUMBER
VARCHAR	VARCHAR	VARCHAR2
VARCHAR	CHAR	CHAR
BINARY	VARBINARY	RAW, BLOB
VARCHAR	TEXT	VARCHAR2
VARCHAR	LONGTEXT	RAW, CBLOB
VARCHAR	MEDIUMTEXT	RAW, CBLOB
VARCHAR	ENUM	VARCHAR2
VARCHAR	SET	VARCHAR2
VARCHAR	bit	CHAR
ARRAY	N/A	N/A
BOOLEAN	N/A	N/A
TUPLE	N/A	N/A
MAP	N/A	N/A
JSON, VARIANT	JSON	JSON
BITMAP	N/A	N/A