Teradata & KADB数据库对象兼容说明(一）

• 兼容说明

本文从Teradata和KADB的数据类型、函数、DDL语句三个方面说明列举两个产品的兼容情况，以此分析从Teradata迁移至KADB的可行性。

• Teradata数据类型兼容

1. 数据类型及兼容性

注：不兼容的数据类型标注为：X

数据类型	是否ANSI扩展	KADB
Array
ARRAY/VARRAY	是	[]
Byte
BLOB[(n)]	是	text
BYTE[(n)]		bytea
VARBYTE[(n)]		bit varying
Numeric
BIGINT	是	bigint
BYTEINT		smallint
DATE		date
DECIMAL [(n[,m])]	是	decimal [ (p, s) ]
DOUBLE PRECISION	是	double precision
FLOAT	是	numeric
INTEGER	是	integer
NUMBER(n[,m])		numeric(n[,m]
NUMBER[(*[,m])]		numeric(n[,m]
NUMERIC [(n[,m])]	是	numeric(n[,m]
REAL	是	real
SMALLINT	是	smallint
DateTime
DATE	是	date
TIME [(n)]	是	time [ (p) ]
TIMESTAMP [(n)]		timestamp [ (p) ]
Interval
INTERVAL	是	interval [ (p) ]
INTERVAL DAY [(n)]	是	INTERVAL DAY [(n)]
INTERVAL DAY [(n)] TO HOUR	是	INTERVAL DAY [(n)] TO HOUR
INTERVAL DAY [(n)] TO MINUTE	是	INTERVAL DAY [(n)] TO MINUTE
INTERVAL DAY [(n)] TO SECOND	是	INTERVAL DAY [(n)] TO SECOND
INTERVAL HOUR [(n)]		INTERVAL HOUR [(n)]
INTERVAL HOUR [(n)] TO MINUTE	是	INTERVAL HOUR [(n)] TO MINUTE
INTERVAL HOUR [(n)] TO SECOND	是	INTERVAL HOUR [(n)] TO SECOND
INTERVAL MINUTE [(n)]	是	INTERVAL MINUTE [(n)]
INTERVAL MINUTE [(n)] TO SECOND [(m)]	是	INTERVAL MINUTE [(n)] TO SECOND [(m)]
INTERVAL MONTH X	是	INTERVAL MONTH X
INTERVAL SECOND [(n,[m])]	是	INTERVAL SECOND [(n,[m])]
INTERVAL YEAR [(n)]	是	INTERVAL YEAR [(n)]
INTERVAL YEAR [(n)] TO MONTH		INTERVAL YEAR [(n)] TO MONTH
Character
CHAR[(n)]	是	char [ (n) ]
CHARACTER(n) CHARACTER SET GRAPHIC	是	char
CLOB	是	text
CHAR VARYING(n)	是	varchar [ (n) ]
LONG VARCHAR	是	text
LONG VARCHAR CHARACTER SET GRAPHIC	是	text
VARCHAR(n)	是	varchar
VARCHAR(n) CHARACTER SET GRAPHIC		varchar
Period
PERIOD(DATE)	是	X
PERIOD(TIME [(n)])	是	X
PERIOD(TIMESTAMP [(n)])	是	X
UDT
udt_name	是	type

• Teradata函数兼容

1. 函数及兼容性

注：不兼容的数据类型标注为：X

函数	KADB
Aggregate Functions
AVG	AVG
COVAR_SAMP	COVAR_SAMP
COVAR_POP	COVAR_POP
UNPIVOT	X
SUM	SUM
STDDEV_SAMP	stddev
STDDEV_POP	STDDEV_POP
SKEW	X
REGR_SYY	REGR_SYY
REGR_SXY	REGR_SXY
REGR_SXX	REGR_SXX
REGR_SLOPE	REGR_SLOPE
REGR_R2	REGR_R2
REGR_INTERCEPT	REGR_INTERCEPT
REGR_COUNT	REGR_COUNT
REGR_AVGY	REGR_AVGY
REGR_AVGX	REGR_AVGX
PIVOT	crosstab
MIN	MIN
MAX	MAX
KURTOSIS	X
GROUPING	GROUPING
COVAR_SAMP	COVAR_SAMP
COVAR_POP	COVAR_POP
COUNT	COUNT
CORR	CORR
Attribute Functions
BIT_LENGTH	BIT_LENGTH
BYTES	X
CHARACTER LENGTH	CHARACTER LENGTH
DEFAULT	X
FORMAT	FORMAT
OCTET_LENGTH	OCTET_LENGTH
TITLE	X
TYPE	X
Bit/Byte Manipulation Functions
BITAND	&
BITNOT	~
BITOR	|
BITXOR	#
COUNTSET	bit_length
GETBIT	get_bit
ROTATELEFT	X
ROTATERIGHT	X
SETBIT	SET_BIT
SHIFTLEFT	X
SHIFTRIGHT	X
SUBBITSTR	substring
TO_BYTE	X
Built-In Functions
ACCOUNT	current_user
CURRENT_DATE/CURDATE	CURRENT_DATE
CURRENT_ROLE	CURRENT_ROLE
CURRENT_TIME/CURTIME	CURRENT_TIME
CURRENT_TIMESTAMP	CURRENT_TIMESTAMP
CURRENT_USER	CURRENT_USER
DATE	DATE
NOW	NOW
SESSION	SESSION
TEMPORAL_DATE	X
TEMPORAL_TIMESTAMP	X
TIME	TIME
USER	USER
Comparison Operators and the Function
DECODE	DECODE
GREATEST	GREATEST
LEAST	LEAST
Null-Handling Functions
NVL	NVL
NVL2	X
Window Aggregate Functions
CSUM	X
CUME_DIST	CUME_DIST
DENSE_RANK	DENSE_RANK
FIRST_VALUE / LAST_VALUE	FIRST_VALUE / LAST_VALUE
LAG/LEAD	LAG/LEAD
MAVG	X
MDIFF	X
MEDIAN	X
MLINREG	X
MSUM	SUM
PERCENT_RANK	PERCENT_RANK
PERCENTILE_CONT / PERCENTILE_DISC	PERCENTILE_CONT/ PERCENTILE_DISC
QUANTILE	X
RANK (ANSI)	RANK (ANSI)
ROW_NUMBER	ROW_NUMBER
String Functions
ASCII	ASCII
CHAR2HEXINT	to_hex
CONCAT	CONCAT
CSV	X
CSVLD	X
EDITDISTANCE	X
INDEX	position
INITCAP	INITCAP
INSTR	INSTR
LEFT	LEFT
LENGTH	LENGTH
LOCATE	position
LOWER	LOWER
LPAD	LPAD
LTRIM	LTRIM
NGRAM	X
NVP	X
OREPLACE	X
OTRANSLATE	X
POSITION	POSITION
REVERSE	REVERSE
RIGHT	RIGHT
RPAD	RPAD
RTRIM	RTRIM
SOUNDEX	SOUNDEX
STRING_CS	X
STRTOK	X
STRTOK_SPLIT_TO_TABLE	X
SUBSTRING/SUBSTR	SUBSTRING/SUBSTR
TRANSLATE	TRANSLATE
TRANSLATE_CHK	X
TRIM	TRIM
UPPER/UCASE	UPPER/UCASE
VARGRAPHIC	X