BUILT-INS(INTRO)

DESCRIPTION
This section describes the data types, functions and operators available to users in Postgres as it is distributed.

Built-in and System Types

BUILT-IN TYPES
This section describes both built-in data types. These Built-in types are are installed in every database.

Users may add new types to Postgres using the define type command described in this manual. User-defined types are not described in this section.

List of built-in types

	POSTGRES Type	Meaning
	abstime	absolute date and time
	aclitem	access control list item
	bool	boolean
	box	2-dimensional rectangle
	bpchar	blank-padded characters
	bytea	variable length array of bytes
	char	character
	char2	array of 2 characters
	char4	array of 4 characters
	char8	array of 8 characters
	char16	array of 16 characters
	cid	command identifier type
	date	ANSI SQL date type
	filename	large object filename
	int	alias for int4
	integer	alias for int4
	int2	two-byte signed integer
	int28	array of 8 int2
	int4	four-byte signed integer
	float	alias for float4
	float4	single-precision floating-point number
	float8	double-precision floating-point number
	lseg	2-dimensional line segment
	name	a multi-character type for storing system identifiers
	oid	object identifier type
	oid8	array of 8 oid
	oidchar16	oid and char16 composed
	oidint2	oid and int2 composed
	oidint4	oid and int4 composed
	path	variable-length array of lseg
	point	2-dimensional geometric point
	polygon	2-dimensional polygon
	real	alias for float4
	regproc	registered procedure
	reltime	relative date and time
	smgr	storage manager
	smallint	alias for int2
	text	variable length array of characters
	tid	tuple identifier type
	time 	ANSI SQL time type
	tinterval	time interval
	varchar	variable-length characters
	xid	transaction identifier type

As a rule, the built-in types are all either (1) internal types, in which case the user should not worry about their external format, or (2) have obvious formats. The exceptions to this rule are the three time types.

Syntax of date and time types

ABSOLUTE TIME
Absolute time is specified using the following syntax:
Month  Day [ Hour : Minute : Second ]  Year [ Timezone ]

where
	Month is Jan, Feb, ..., Dec
	Day is 1, 2, ..., 31
	Hour is 01, 02, ..., 24
	Minute is 00, 01, ..., 59
	Second is 00, 01, ..., 59
	Year is 1901, 1902, ..., 2038
Valid dates are from Dec 13 20:45:53 1901 GMT to Jan 19 03:14:04 2038 GMT. As of Version 3.0, times are no longer read and written using Greenwich Mean Time; the input and output routines default to the local time zone.

The special absolute time values “current”, “infinity” and “-infinity” are also provided. “infinity” specifies a time later than any valid time, and “-infinity” specifies a time earlier than any valid time. “current” indicates that the current time should be substituted whenever this value appears in a computation.

The strings “now” and “epoch” can be used to specify time values. “now” means the current time, and differs from “current” in that the current time is immediately substituted for it. “epoch” means Jan 1 00:00:00 1970 GMT.

RELATIVE TIME
Relative time is specified with the following syntax:
@ Quantity Unit [Direction]

where
	Quantity is `1', `2', ...
	Unit is ``second'', ``minute'', ``hour'', ``day'', ``week'',
	``month'' (30-days), or ``year'' (365-days),
	or PLURAL of these units.
	Direction is ``ago''

(Note: Valid relative times are less than or equal to 68 years.) In addition, the special relative time “Undefined RelTime” is provided.

TIME RANGES
Time ranges are specified as:
[ 'abstime' 'abstime']
where abstime is a time in the absolute time format. Special abstime values such as “current”, “infinity” and “-infinity” can be used.

Built-in operators and functions

OPERATORS
Postgres provides a large number of built-in operators on system types. These operators are declared in the system catalog “pg_operator”. Every entry in “pg_operator” includes the object ID of the procedure that implements the operator.

Users may invoke operators using the operator name, as in
select * from emp where salary < 40000;
Alternatively, users may call the functions that implement the operators directly. In this case, the query above would be expressed as
select * from emp where int4lt(salary, 40000);
The rest of this section provides a list of the built-in operators and the functions that implement them. Binary operators are listed first, followed by unary operators.

BINARY OPERATORS
This list was generated from the Postgres system catalogs with the query:
SELECT
	t0.typname AS result,
        t1.typname AS left_type,
        t2.typname AS right_type,
        o.oprname AS operatr,
        p.proname AS func_name
FROM 	pg_proc p, pg_type t0,
        pg_type t1, pg_type t2,
        pg_operator o
WHERE 	p.prorettype = t0.oid AND
        RegprocToOid(o.oprcode) = p.oid AND
	p.pronargs = 2 AND
	o.oprleft = t1.oid AND
	o.oprright = t2.oid
ORDER BY result, left_type, right_type, operatr;
These operations are cast in terms of SQL types and so are not directly usable as C function prototypes.
Operators:
general
	<	less or equal
	<>	inequality
	<	less than
	<	greater or equal
	>	greater or equal
	>	greater than
		equality
	~	A matches regular expression B, case-sensitive
	!~	A does not match regular expression B, case-sensitive
	~*	A matches regular expression B, case-insensitive.
	!~*	A does not match regular expression B, case-insensitive
	~~	A matches LIKE expression B, case-sensitive
	!~~	A does not match LIKE expression B, case-sensitive
	+	addition
	-	subtraction
	*	multiplication
	/	division
	%	modulus
	@	absolute value
float8
	^	exponentiation
	%	truncate to integer
	|/	square root
	||/	cube root
	:	exponential function
	;	natural logarithm (in psql, protect with parentheses)
point
	!<	A is left of B
	!>	A is right of B
	!^	A is above B
	!|	A is below B
	|	equality
	===>	point inside box
	===`	point on path
	<===>	distance between points
box
	&&	boxes overlap
	&<	box A overlaps box B, but does not extend to right of box B
	&>	box A overlaps box B, but does not extend to left of box B
	<<	A is left of B
		area equal
	<	area less than
	<	area less or equal
	>	area greater or equal
	>	area greater than
	>>	A is right of B
	@	A is contained in B
	~	box equality
	~=	A same as B
	~	A contains B
	@@	center of box
polygon
	&&	polygons overlap
	&<	A overlaps B but does not extend to right of B
	&>	A overlaps B but does not extend to left of B
	<<	A is left of B
	>>	A is right of B
	@	A is contained by B
	~	equality
	~=	A same as B
	~	A contains B
tinterval
	#<	interval length less or equal reltime
	#<>	interval length not equal to reltime.
	#<	interval length less than reltime
	#	interval length equal to reltime
	#>	interval length greater or equal reltime
	#>	interval length greater than reltime
	&&	intervals overlap
	<<	A contains B
		equality
	<>	interval bounded by two abstimes
	<?>	abstime in tinterval
	|	start of interval
	<#>	convert to interval
result   |left_type |right_type|operatr|func_name
---------+----------+----------+-------+---------------
_aclitem |_aclitem  |aclitem   |+      |aclinsert
_aclitem |_aclitem  |aclitem   |-      |aclremove
abstime  |abstime   |reltime   |+      |timepl
abstime  |abstime   |reltime   |-      |timemi
bool     |_abstime  |_abstime  |=      |array_eq
bool     |_aclitem  |_aclitem  |=      |array_eq
bool     |_aclitem  |aclitem   |~      |aclcontains
bool     |_bool     |_bool     |=      |array_eq
bool     |_box      |_box      |=      |array_eq
bool     |_bytea    |_bytea    |=      |array_eq
bool     |_char     |_char     |=      |array_eq
bool     |_char16   |_char16   |=      |array_eq
bool     |_cid      |_cid      |=      |array_eq
bool     |_filename |_filename |=      |array_eq
bool     |_float4   |_float4   |=      |array_eq
bool     |_float8   |_float8   |=      |array_eq
bool     |_int2     |_int2     |=      |array_eq
bool     |_int28    |_int28    |=      |array_eq
bool     |_int4     |_int4     |=      |array_eq
bool     |_lseg     |_lseg     |=      |array_eq
bool     |_name     |_name     |=      |array_eq
bool     |_oid      |_oid      |=      |array_eq
bool     |_oid8     |_oid8     |=      |array_eq
bool     |_path     |_path     |=      |array_eq
bool     |_point    |_point    |=      |array_eq
bool     |_polygon  |_polygon  |=      |array_eq
bool     |_ref      |_ref      |=      |array_eq
bool     |_regproc  |_regproc  |=      |array_eq
bool     |_reltime  |_reltime  |=      |array_eq
bool     |_stub     |_stub     |=      |array_eq
bool     |_text     |_text     |=      |array_eq
bool     |_tid      |_tid      |=      |array_eq
bool     |_tinterval|_tinterval|=      |array_eq
bool     |_xid      |_xid      |=      |array_eq
bool     |abstime   |abstime   |<      |abstimelt
bool     |abstime   |abstime   |<=     |abstimele
bool     |abstime   |abstime   |<>     |abstimene
bool     |abstime   |abstime   |=      |abstimeeq
bool     |abstime   |abstime   |>      |abstimegt
bool     |abstime   |abstime   |>=     |abstimege
bool     |abstime   |tinterval |<?>    |ininterval
bool     |bool      |bool      |<>     |boolne
bool     |bool      |bool      |=      |booleq
bool     |box       |box       |&&     |box_overlap
bool     |box       |box       |&<     |box_overleft
bool     |box       |box       |&>     |box_overright
bool     |box       |box       |<      |box_lt
bool     |box       |box       |<<     |box_left
bool     |box       |box       |<=     |box_le
bool     |box       |box       |=      |box_eq
bool     |box       |box       |>      |box_gt
bool     |box       |box       |>=     |box_ge
bool     |box       |box       |>>     |box_right
bool     |box       |box       |@      |box_contained
bool     |box       |box       |~      |box_contain
bool     |box       |box       |~=     |box_same
bool     |bpchar    |bpchar    |<      |bpcharlt
bool     |bpchar    |bpchar    |<=     |bpcharle
bool     |bpchar    |bpchar    |<>     |bpcharne
bool     |bpchar    |bpchar    |=      |bpchareq
bool     |bpchar    |bpchar    |>      |bpchargt
bool     |bpchar    |bpchar    |>=     |bpcharge
bool     |bpchar    |text      |!~     |textregexne
bool     |bpchar    |text      |!~*    |texticregexne
bool     |bpchar    |text      |!~~    |textnlike
bool     |bpchar    |text      |~      |textregexeq
bool     |bpchar    |text      |~*     |texticregexeq
bool     |bpchar    |text      |~~     |textlike
bool     |char      |char      |<      |charlt
bool     |char      |char      |<=     |charle
bool     |char      |char      |<>     |charne
bool     |char      |char      |=      |chareq
bool     |char      |char      |>      |chargt
bool     |char      |char      |>=     |charge
bool     |char16    |char16    |<      |char16lt
bool     |char16    |char16    |<=     |char16le
bool     |char16    |char16    |<>     |char16ne
bool     |char16    |char16    |=      |char16eq
bool     |char16    |char16    |>      |char16gt
bool     |char16    |char16    |>=     |char16ge
bool     |char16    |text      |!~     |char16regexne
bool     |char16    |text      |!~*    |char16icregexne
bool     |char16    |text      |!~~    |char16nlike
bool     |char16    |text      |!~~    |char16nlike
bool     |char16    |text      |~      |char16regexeq
bool     |char16    |text      |~*     |char16icregexeq
bool     |char16    |text      |~~     |char16like
bool     |char16    |text      |~~     |char16like
bool     |char2     |char2     |<      |char2lt
bool     |char2     |char2     |<=     |char2le
bool     |char2     |char2     |<>     |char2ne
bool     |char2     |char2     |=      |char2eq
bool     |char2     |char2     |>      |char2gt
bool     |char2     |char2     |>=     |char2ge
bool     |char2     |text      |!~     |char2regexne
bool     |char2     |text      |!~*    |char2icregexne
bool     |char2     |text      |!~~    |char2nlike
bool     |char2     |text      |~      |char2regexeq
bool     |char2     |text      |~*     |char2icregexeq
bool     |char2     |text      |~~     |char2like
bool     |char4     |char4     |<      |char4lt
bool     |char4     |char4     |<=     |char4le
bool     |char4     |char4     |<>     |char4ne
bool     |char4     |char4     |=      |char4eq
bool     |char4     |char4     |>      |char4gt
bool     |char4     |char4     |>=     |char4ge
bool     |char4     |text      |!~     |char4regexne
bool     |char4     |text      |!~*    |char4icregexne
bool     |char4     |text      |!~~    |char4nlike
bool     |char4     |text      |~      |char4regexeq
bool     |char4     |text      |~*     |char4icregexeq
bool     |char4     |text      |~~     |char4like
bool     |char8     |char8     |<      |char8lt
bool     |char8     |char8     |<=     |char8le
bool     |char8     |char8     |<>     |char8ne
bool     |char8     |char8     |=      |char8eq
bool     |char8     |char8     |>      |char8gt
bool     |char8     |char8     |>=     |char8ge
bool     |char8     |text      |!~     |char8regexne
bool     |char8     |text      |!~*    |char8icregexne
bool     |char8     |text      |!~~    |char8nlike
bool     |char8     |text      |~      |char8regexeq
bool     |char8     |text      |~*     |char8icregexeq
bool     |char8     |text      |~~     |char8like
bool     |date      |date      |<      |date_lt
bool     |date      |date      |<=     |date_le
bool     |date      |date      |<>     |date_ne
bool     |date      |date      |=      |date_eq
bool     |date      |date      |>      |date_gt
bool     |date      |date      |>=     |date_ge
bool     |float4    |float4    |<      |float4lt
bool     |float4    |float4    |<=     |float4le
bool     |float4    |float4    |<>     |float4ne
bool     |float4    |float4    |=      |float4eq
bool     |float4    |float4    |>      |float4gt
bool     |float4    |float4    |>=     |float4ge
bool     |float4    |float8    |<      |float48lt
bool     |float4    |float8    |<=     |float48le
bool     |float4    |float8    |<>     |float48ne
bool     |float4    |float8    |=      |float48eq
bool     |float4    |float8    |>      |float48gt
bool     |float4    |float8    |>=     |float48ge
bool     |float8    |float4    |<      |float84lt
bool     |float8    |float4    |<=     |float84le
bool     |float8    |float4    |<>     |float84ne
bool     |float8    |float4    |=      |float84eq
bool     |float8    |float4    |>      |float84gt
bool     |float8    |float4    |>=     |float84ge
bool     |float8    |float8    |<      |float8lt
bool     |float8    |float8    |<=     |float8le
bool     |float8    |float8    |<>     |float8ne
bool     |float8    |float8    |=      |float8eq
bool     |float8    |float8    |>      |float8gt
bool     |float8    |float8    |>=     |float8ge
bool     |int2      |int2      |<      |int2lt
bool     |int2      |int2      |<=     |int2le
bool     |int2      |int2      |<>     |int2ne
bool     |int2      |int2      |=      |int2eq
bool     |int2      |int2      |>      |int2gt
bool     |int2      |int2      |>=     |int2ge
bool     |int4      |int4      |<      |int4lt
bool     |int4      |int4      |<=     |int4le
bool     |int4      |int4      |<>     |int4ne
bool     |int4      |int4      |=      |int4eq
bool     |int4      |int4      |>      |int4gt
bool     |int4      |int4      |>=     |int4ge
bool     |int4      |name      |!!=    |int4notin
bool     |int4      |oid       |=      |int4eqoid
bool     |name      |name      |<      |namelt
bool     |name      |name      |<=     |namele
bool     |name      |name      |<>     |namene
bool     |name      |name      |=      |nameeq
bool     |name      |name      |>      |namegt
bool     |name      |name      |>=     |namege
bool     |name      |text      |!~     |nameregexne
bool     |name      |text      |!~*    |nameicregexne
bool     |name      |text      |!~~    |namenlike
bool     |name      |text      |~      |nameregexeq
bool     |name      |text      |~*     |nameicregexeq
bool     |name      |text      |~~     |namelike
bool     |oid       |int4      |=      |oideqint4
bool     |oid       |name      |!!=    |oidnotin
bool     |oid       |oid       |<      |int4lt
bool     |oid       |oid       |<=     |int4le
bool     |oid       |oid       |<>     |oidne
bool     |oid       |oid       |=      |oideq
bool     |oid       |oid       |>      |int4gt
bool     |oid       |oid       |>=     |int4ge
bool     |oidint2   |oidint2   |<      |oidint2lt
bool     |oidint2   |oidint2   |<=     |oidint2le
bool     |oidint2   |oidint2   |<>     |oidint2ne
bool     |oidint2   |oidint2   |=      |oidint2eq
bool     |oidint2   |oidint2   |>      |oidint2gt
bool     |oidint2   |oidint2   |>=     |oidint2ge
bool     |oidint4   |oidint4   |<      |oidint4lt
bool     |oidint4   |oidint4   |<=     |oidint4le
bool     |oidint4   |oidint4   |<>     |oidint4ne
bool     |oidint4   |oidint4   |=      |oidint4eq
bool     |oidint4   |oidint4   |>      |oidint4gt
bool     |oidint4   |oidint4   |>=     |oidint4ge
bool     |oidname   |oidname   |<      |oidnamelt
bool     |oidname   |oidname   |<=     |oidnamele
bool     |oidname   |oidname   |<>     |oidnamene
bool     |oidname   |oidname   |=      |oidnameeq
bool     |oidname   |oidname   |>      |oidnamegt
bool     |oidname   |oidname   |>=     |oidnamege
bool     |point     |box       |===>   |on_pb
bool     |point     |path      |===`   |on_ppath
bool     |point     |point     |!<     |point_left
bool     |point     |point     |!>     |point_right
bool     |point     |point     |!^     |point_above
bool     |point     |point     |!    |point_below
bool     |point     |point     |==   |point_eq
bool     |polygon   |polygon   |&&     |poly_overlap
bool     |polygon   |polygon   |&<     |poly_overleft
bool     |polygon   |polygon   |&>     |poly_overright
bool     |polygon   |polygon   |<<     |poly_left
bool     |polygon   |polygon   |>>     |poly_right
bool     |polygon   |polygon   |@      |poly_contained
bool     |polygon   |polygon   |~      |poly_contain
bool     |polygon   |polygon   |~=     |poly_same
bool     |reltime   |reltime   |<      |reltimelt
bool     |reltime   |reltime   |<=     |reltimele
bool     |reltime   |reltime   |<>     |reltimene
bool     |reltime   |reltime   |=      |reltimeeq
bool     |reltime   |reltime   |>      |reltimegt
bool     |reltime   |reltime   |>=     |reltimege
bool     |text      |text      |!~     |textregexne
bool     |text      |text      |!~*    |texticregexne
bool     |text      |text      |!~~    |textnlike
bool     |text      |text      |<      |text_lt
bool     |text      |text      |<=     |text_le
bool     |text      |text      |<>     |textne
bool     |text      |text      |=      |texteq
bool     |text      |text      |>      |text_gt
bool     |text      |text      |>=     |text_ge
bool     |text      |text      |~      |textregexeq
bool     |text      |text      |~*     |texticregexeq
bool     |text      |text      |~~     |textlike
bool     |time      |time      |<      |time_lt
bool     |time      |time      |<=     |time_le
bool     |time      |time      |<>     |time_ne
bool     |time      |time      |=      |time_eq
bool     |time      |time      |>      |time_gt
bool     |time      |time      |>=     |time_ge
bool     |tinterval |reltime   |#<     |intervallenlt
bool     |tinterval |reltime   |#<=    |intervallenle
bool     |tinterval |reltime   |#<>    |intervallenne
bool     |tinterval |reltime   |#=     |intervalleneq
bool     |tinterval |reltime   |#>     |intervallengt
bool     |tinterval |reltime   |#>=    |intervallenge
bool     |tinterval |tinterval |&&     |intervalov
bool     |tinterval |tinterval |<<     |intervalct
bool     |tinterval |tinterval |=      |intervaleq
bool     |varchar   |text      |!~     |textregexne
bool     |varchar   |text      |!~*    |texticregexne
bool     |varchar   |text      |!~~    |textnlike
bool     |varchar   |text      |~      |textregexeq
bool     |varchar   |text      |~*     |texticregexeq
bool     |varchar   |text      |~~     |textlike
bool     |varchar   |varchar   |<      |varcharlt
bool     |varchar   |varchar   |<=     |varcharle
bool     |varchar   |varchar   |<>     |varcharne
bool     |varchar   |varchar   |=      |varchareq
bool     |varchar   |varchar   |>      |varchargt
bool     |varchar   |varchar   |>=     |varcharge
char     |char      |char      |*      |charmul
char     |char      |char      |+      |charpl
char     |char      |char      |-      |charmi
char     |char      |char      |/      |chardiv
float4   |float4    |float4    |*      |float4mul
float4   |float4    |float4    |+      |float4pl
float4   |float4    |float4    |-      |float4mi
float4   |float4    |float4    |/      |float4div
float8   |float4    |float8    |*      |float48mul
float8   |float4    |float8    |+      |float48pl
float8   |float4    |float8    |-      |float48mi
float8   |float4    |float8    |/      |float48div
float8   |float8    |float4    |*      |float84mul
float8   |float8    |float4    |+      |float84pl
float8   |float8    |float4    |-      |float84mi
float8   |float8    |float4    |/      |float84div
float8   |float8    |float8    |*      |float8mul
float8   |float8    |float8    |+      |float8pl
float8   |float8    |float8    |-      |float8mi
float8   |float8    |float8    |/      |float8div
float8   |float8    |float8    |^      |dpow
int2     |int2      |int2      |%      |int2mod
int2     |int2      |int2      |*      |int2mul
int2     |int2      |int2      |+      |int2pl
int2     |int2      |int2      |-      |int2mi
int2     |int2      |int2      |/      |int2div
int4     |int2      |int4      |%      |int24mod
int4     |int2      |int4      |*      |int24mul
int4     |int2      |int4      |+      |int24pl
int4     |int2      |int4      |-      |int24mi
int4     |int2      |int4      |/      |int24div
int4     |int2      |int4      |<      |int24lt
int4     |int2      |int4      |<=     |int24le
int4     |int2      |int4      |<>     |int24ne
int4     |int2      |int4      |=      |int24eq
int4     |int2      |int4      |>      |int24gt
int4     |int2      |int4      |>=     |int24ge
int4     |int4      |int2      |%      |int42mod
int4     |int4      |int2      |*      |int42mul
int4     |int4      |int2      |+      |int42pl
int4     |int4      |int2      |-      |int42mi
int4     |int4      |int2      |/      |int42div
int4     |int4      |int2      |<      |int42lt
int4     |int4      |int2      |<=     |int42le
int4     |int4      |int2      |<>     |int42ne
int4     |int4      |int2      |=      |int42eq
int4     |int4      |int2      |>      |int42gt
int4     |int4      |int2      |>=     |int42ge
int4     |int4      |int4      |%      |int4mod
int4     |int4      |int4      |*      |int4mul
int4     |int4      |int4      |+      |int4pl
int4     |int4      |int4      |-      |int4mi
int4     |int4      |int4      |/      |int4div
int4     |point     |point     |<===>  |pointdist
tinterval|abstime   |abstime   |<#>    |mktinterval

LEFT UNARY OPERATORS
The table below gives the left unary operators that are registered in the system catalogs. This list was generated from the Postgres system catalogs with the query:
SELECT o.oprname AS left_unary,
       right.typname AS operand,
       result.typname AS return_type
FROM pg_operator o, pg_type right, pg_type result
WHERE o.oprkind = 'l' AND          -- left unary
      o.oprright = right.oid AND
      o.oprresult = result.oid
ORDER BY operand;
left_unary|operand  |return_type
----------+---------+-----------
@@        |box      |point
@         |float4   |float4
-         |float4   |float4
;         |float8   |float8
:         |float8   |float8
%         |float8   |float8
/     |float8   |float8
/       |float8   |float8
@         |float8   |float8
-         |float8   |float8
-         |int2     |int2
-         |int4     |int4
!!        |int4     |int4
        |tinterval|abstime

RIGHT UNARY OPERATORS
The table below gives the right unary operators that are registered in the system catalogs. This list was generated from the Postgres system catalogs with the query:
SELECT o.oprname AS right_unary,
       left.typname AS operand,
       result.typname AS return_type
FROM pg_operator o, pg_type left, pg_type result
WHERE o.oprkind = 'r' AND          -- right unary
      o.oprleft = left.oid AND
      o.oprresult = result.oid
ORDER BY operand;
right_unary|operand|return_type
-----------+-------+-----------
%          |float8 |float8
!          |int4   |int4

AGGREGATE FUNCTIONS
The table below gives the aggregate functions that are registered in the system catalogs. This list was generated from the Postgres system catalogs with the query:
SELECT a.aggname, t.typname
FROM pg_aggregate a, pg_type t
WHERE a.aggbasetype = t.oid
ORDER BY aggname, typname;
aggname|typname
-------+-------
avg    |float4
avg    |float8
avg    |int2
avg    |int4
max    |float4
max    |float8
max    |int2
max    |int4
min    |float4
min    |float8
min    |int2
min    |int4
sum    |float4
sum    |float8
sum    |int2
sum    |int4
count is also available.

SEE ALSO
For examples on specifying literals of built-in types, see SQL(l).

BUGS

Although most of the input and output functions correponding to the base types (e.g., integers and floating point numbers) do some error-checking, none of them are particularly rigorous about it. More importantly, almost none of the operators and functions (e.g., addition and multiplication) perform any error-checking at all. Consequently, many of the numeric operations will (for example) silently underflow or overflow.

Some of the input and output functions are not invertible. That is, the result of an output function may lose precision when compared to the original input.