PGBUILTIN(INTRO)

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

PGBUILTIN TYPES
This section describes pgbuiltin data types. These Built-in types 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) limited-range 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
	datetime	general-use date and time
	filename	large object filename
	int2	two-byte signed integer
	int28	array of 8 int2
	int4	four-byte signed integer
	float4	single-precision floating-point number
	float8	double-precision floating-point number
	lseg	2-dimensional line segment
	money	decimal type with fixed precision
	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	open or closed line segments
	point	2-dimensional geometric point
	polygon	2-dimensional polygon (same as a closed path)
	circle	2-dimensional circle (center and radius)
	regproc	registered procedure
	reltime	(relative) date and time span (duration)
	smgr	storage manager
	text	variable length array of characters
	tid	tuple identifier type
	time 	ANSI SQL time type
	timespan	general-use time span (duration)
	timestamp	limited-range ISO-format date and time
	tinterval	time interval (start and stop abstime)
	varchar	variable-length characters
	xid	transaction identifier type

There are some data types defined by SQL/92 syntax which are mapped directly into native Postgres types. Note that the "exact numerics" decimal and numeric have fully implemented syntax but currently (postgres v6.2) support only a limited range of the values allowed by SQL/92.

List of SQL/92 types

	POSTGRES Type	SQL/92 Type	Meaning
	char(n)	character(n)	fixed-length character string
	varchar(n)	character varying(n)	variable-length character string
	float4/8	float(p)	floating-point number with precision p
	float8	double precision	double-precision floating-point number
	float8	real	double-precision floating-point number
	int2	smallint	signed two-byte integer
	int4	int	signed 4-byte integer
	int4	integer	signed 4-byte integer
	int4	decimal(p,s)	exact numeric for p <= 9, s = 0
	int4	numeric(p,s)	exact numeric for p == 9, s = 0
	timestamp	timestamp with time zone	date/time
	timespan	interval	general-use time span

There are some constants and functions defined in SQL/92.

List of SQL/92 constants

	SQL/92 Function	Meaning
	current_date	date of current transaction
	current_time	time of current transaction
	current_timestamp	date and time of current transaction

Many of the built-in types have obvious external formats. However, several types are either unique to Postgres, such as open and closed paths, or have several possibilities for formats, such as date and time types.

Syntax of date and time types
Most date and time types share code for data input. For those types ( datetime, abstime, timestamp, timespan, reltime, date, and time) the input can have any of a wide variety of styles. For numeric date representations, European and US conventions can differ, and the proper interpretation is obtained by using the set(l) command before entering data. Output formats can be set to one of three styles: ISO-8601, SQL (traditional Oracle/Ingres), and traditional Postgres (see section on absolute time) with the SQL style having European and US variants (see set(l)). In future releases, the number of date/time types will decrease, with the current implementation of datetime becoming timestamp, timespan becoming interval, and (possibly) abstime and reltime being deprecated in favor of timestamp and interval.

DATETIME
General-use date and time is input using a wide range of styles, including ISO-compatible, SQL-compatible, traditional Postgres (see section on absolute time) and other permutations of date and time. Output styles can be ISO-compatible, SQL-compatible, or traditional Postgres, with the default set to be compatible with Postgres v6.0.

datetime is specified using the following syntax:

Year-Month-Day [ Hour : Minute : Second ]      [AD,BC] [ Timezone ]
  YearMonthDay [ Hour : Minute : Second ]      [AD,BC] [ Timezone ]
     Month Day [ Hour : Minute : Second ] Year [AD,BC] [ Timezone ]

where
	Year is 4013 BC, ..., very large
	Month is Jan, Feb, ..., Dec or 1, 2, ..., 12
	Day is 1, 2, ..., 31
	Hour is 00, 02, ..., 23
	Minute is 00, 01, ..., 59
	Second is 00, 01, ..., 59 (60 for leap second)
	Timezone is 3 characters or ISO offset to GMT

Valid dates are from Nov 13 00:00:00 4013 BC GMT to far into the future. Timezones are either three characters (e.g. "GMT" or "PST") or ISO-compatible offsets to GMT (e.g. "-08" or "-08:00" when in Pacific Standard Time). Dates are stored internally in Greenwich Mean Time. Input and output routines translate time to the local time zone of the server.

The special values `current', `infinity' and `-infinity' are 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', `today', `yesterday', `tomorrow', 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.

TIMESPAN
General-use time span is input using a wide range of syntaxes, including ISO-compatible, SQL-compatible, traditional Postgres (see section on relative time ) and other permutations of time span. Output formats can be ISO-compatible, SQL-compatible, or traditional Postgres, with the default set to be Postgres-compatible. Months and years are a "qualitative" time interval, and are stored separately from the other "quantitative" time intervals such as day or hour. For date arithmetic, the qualitative time units are instantiated in the context of the relevant date or time.

Time span is specified with the following syntax:

  Quantity Unit [Quantity Unit...] [Direction]
@ Quantity Unit [Direction]

where
	Quantity is ..., `-1', `0', `1', `2', ...
	Unit is `second', `minute', `hour', `day', `week', `month', `year',
	or abbreviations or plurals of these units.
	Direction is `ago'.

ABSOLUTE TIME
Absolute time (abstime) is a limited-range (+/- 68 years) and limited-precision (1 sec) date data type. datetime may be preferred, since it covers a larger range with greater precision.

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.

All special values allowed for datetime are also allowed for absolute time.

RELATIVE TIME
Relative time (reltime) is a limited-range (+/- 68 years) and limited-precision (1 sec) time span data type. timespan may be preferred, since it covers a larger range with greater precision, allows multiple units for an entry, and correctly handles qualitative time units such as year and month. For reltime, only one quantity and unit is allowed per entry, which can be inconvenient for complicated time spans.

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.

TIMESTAMP
This is currently a limited-range absolute time which closely resembles the abstime data type. It shares the general input parser with the other date/time types. In future releases this type will absorb the capabilities of the datetime type and will move toward SQL92 compliance.

timestamp is specified using the same syntax as for datetime.

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.

Syntax of geometric types

POINT
Points are specified using the following syntax:

( x , y )
  x , y

where
	x is the x-axis coordinate as a floating point number
	y is the y-axis coordinate as a floating point number

LSEG
Line segments are represented by pairs of points.

lseg is specified using the following syntax:

( ( x1 , y1 ) , ( x2 , y2 ) )
  ( x1 , y1 ) , ( x2 , y2 )
    x1 , y1   ,   x2 , y2

where
	(x1,y1) and (x2,y2) are the endpoints of the segment

BOX
Boxes are represented by pairs of points which are opposite corners of the box.

box is specified using the following syntax:

( ( x1 , y1 ) , ( x2 , y2 ) )
  ( x1 , y1 ) , ( x2 , y2 )
    x1 , y1   ,   x2 , y2

where
	(x1,y1) and (x2,y2) are opposite corners

Boxes are output using the first syntax. The corners are reordered on input to store the lower left corner first and the upper right corner last. Other corners of the box can be entered, but the lower left and upper right corners are determined from the input and stored.

PATH
Paths are represented by sets of points. Paths can be "open", where the first and last points in the set are not connected, and "closed", where the first and last point are connected. Functions popen(p) and pclose(p) are supplied to force a path to be open or closed, and functions isopen(p) and isclosed(p) are supplied to select either type in a query.

path is specified using the following syntax:

( ( x1 , y1 ) , ... , ( xn , yn ) )
[ ( x1 , y1 ) , ... , ( xn , yn ) ]
  ( x1 , y1 ) , ... , ( xn , yn )
  ( x1 , y1   , ... ,   xn , yn )
    x1 , y1   , ... ,   xn , yn

where
	(x1,y1),...,(xn,yn) are points 1 through n
	a leading "[" indicates an open path
	a leading "(" indicates a closed path

Paths are output using the first syntax. Note that Postgres versions prior to v6.1 used a format for paths which had a single leading parenthesis, a "closed" flag, an integer count of the number of points, then the list of points followed by a closing parenthesis. The built-in function upgradepath() is supplied to convert paths dumped and reloaded from pre-v6.1 databases.

POLYGON
Polygons are represented by sets of points. Polygons should probably be considered equivalent to closed paths, but are stored differently and have their own set of support routines.

polygon is specified using the following syntax:

( ( x1 , y1 ) , ... , ( xn , yn ) )
  ( x1 , y1 ) , ... , ( xn , yn )
  ( x1 , y1   , ... ,   xn , yn )
    x1 , y1   , ... ,   xn , yn

where
	(x1,y1),...,(xn,yn) are points 1 through n

Polygons are output using the first syntax. The last format is supplied to be backward compatible with v6.0 and earlier path formats and will not be supported in future versions of Postgres.
    a single leading "(" indicates a v6.0-compatible format ( x1 , ... , xn , y1 , ... , yn ) Note that Postgres versions prior to v6.1 used a format for polygons which had a single leading parenthesis, the list of x-axis coordinates, the list of y-axis coordinates, followed by a closing parenthesis. The built-in function upgradepoly() is supplied to convert polygons dumped and reloaded from pre-v6.1 databases.

CIRCLE
Circles are represented by a center point and a radius.

circle is specified using the following syntax:

< ( x , y ) , r >
( ( x , y ) , r )
  ( x , y ) , r
    x , y   , r

where
	(x,y) is the center of the circle
	r is the radius of the circle

Circles are output using the first syntax.

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
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
geometric
	@	A contained by (inside or on) B
	~	A contains (around or on) B
	@@	center of object
	<->	distance between A and B
	&&	objects 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 above B
	<^	A is below B
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
	~	A same as B (equality)
	@	point inside (or on) path, box, circle, polygon
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
	>>	A is right of B
	>^	A is above B
	<^	A is below B
		area equal
	<	area less than
	<	area less or equal
	>	area greater or equal
	>	area greater than
	~	A same as B (equality)
	@	A is contained in 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 same as B (equality)
	@	A is contained by B
	~	A contains B
circle
	&&	circles 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 above B
	<^	A is below B
	~	A same as B (equality)
	@	A is contained by 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

FUNCTIONS
Many data types have functions available for conversion to other related types. In addition, there are some type-specific functions. Functions which are also available through operators are documented as operators only.

Some functions defined for text are also available for char() and varchar().

For the date_part() and date_trunc() functions, arguments can be `year', `month', `day', `hour', `minute', and `second', as well as the more specialized quantities `decade', `century', `millenium', `millisecond', and `microsecond'. date_part() allows `dow' to return day of week and `epoch' to return seconds since 1970 for datetime and 'epoch' to return total elapsed seconds for timespan.
Functions:
integer
    float8   float(int)                convert integer to floating point
    float4   float4(int)               convert integer to floating point
float
    int      integer(float)            convert floating point to integer
text
    text     lower(text)               convert text to lower case
    text     lpad(text,int,text)       left pad string to specified length
    text     ltrim(text,text)          left trim characters from text
    text     position(text,text)       extract specified substring
    text     rpad(text,int,text)       right pad string to specified length
    text     rtrim(text,text)          right trim characters from text
    text     substr(text,int[,int])    extract specified substring
    text     upper(text)               convert text to upper case
abstime
	bool     isfinite(abstime)         TRUE if this is a finite time
	datetime datetime(abstime)         convert to datetime
date
	datetime datetime(date)            convert to datetime
	datetime datetime(date,time)       convert to datetime
datetime
	timespan age(datetime,datetime)    date difference preserving months and years
	float8   date_part(text,datetime)  specified portion of date field
	datetime date_trunc(text,datetime) truncate date at specified units
	bool     isfinite(datetime)        TRUE if this is a finite time
	abstime  abstime(datetime)         convert to abstime
reltime
	timespan timespan(reltime)         convert to timespan
time
	datetime datetime(date,time)       convert to datetime
timespan
	float8   date_part(text,timespan)  specified portion of time field
	bool     isfinite(timespan)        TRUE if this is a finite time
	reltime  reltime(timespan)         convert to reltime
box
	box      box(point,point)          convert points to box
	float8   area(box)                 area of box
path
	bool     isopen(path)              TRUE if this is an open path
	bool     isclosed(path)            TRUE if this is a closed path
circle
	circle   circle(point,float8)      convert to circle
	polygon  polygon(npts,circle)      convert to polygon with npts points
	float8   center(circle)            radius of circle
	float8   radius(circle)            radius of circle
	float8   diameter(circle)          diameter of circle
	float8   area(circle)              area of circle

SQL/92 defines functions with specific syntax. Some of these are implemented using other Postgres functions.
SQL/92 Functions:
text
    text     position(text in text)    extract specified substring
    text     substring(text [from int] [for int])
                                       extract specified substring
    text     trim([leading|trailing|both] [text] from text)
                                       trim characters from text

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.
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      |<      |boollt
bool     |bool      |bool      |<>     |boolne
bool     |bool      |bool      |=      |booleq
bool     |bool      |bool      |>      |boolgt
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_below
bool     |box       |box       |=      |box_eq
bool     |box       |box       |>      |box_gt
bool     |box       |box       |>=     |box_ge
bool     |box       |box       |>>     |box_right
bool     |box       |box       |>^     |box_above
bool     |box       |box       |?#     |box_overlap
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      |~      |char16regexeq
bool     |char16    |text      |~*     |char16icregexeq
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     |circle    |circle    |&&     |circle_overlap
bool     |circle    |circle    |&<     |circle_overleft
bool     |circle    |circle    |&>     |circle_overright
bool     |circle    |circle    |<      |circle_lt
bool     |circle    |circle    |<<     |circle_left
bool     |circle    |circle    |<=     |circle_le
bool     |circle    |circle    |<>     |circle_ne
bool     |circle    |circle    |<^     |circle_below
bool     |circle    |circle    |=      |circle_eq
bool     |circle    |circle    |>      |circle_gt
bool     |circle    |circle    |>=     |circle_ge
bool     |circle    |circle    |>>     |circle_right
bool     |circle    |circle    |>^     |circle_above
bool     |circle    |circle    |@      |circle_contained
bool     |circle    |circle    |~      |circle_contain
bool     |circle    |circle    |~=     |circle_same
bool     |circle    |point     |~      |circle_contain_pt
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     |datetime  |datetime  |<      |datetime_lt
bool     |datetime  |datetime  |<=     |datetime_le
bool     |datetime  |datetime  |<>     |datetime_ne
bool     |datetime  |datetime  |=      |datetime_eq
bool     |datetime  |datetime  |>      |datetime_gt
bool     |datetime  |datetime  |>=     |datetime_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     |line      |box       |?#     |inter_lb
bool     |lseg      |box       |?#     |inter_sb
bool     |lseg      |box       |@      |on_sb
bool     |lseg      |line      |?#     |inter_sl
bool     |lseg      |line      |@      |on_sl
bool     |lseg      |lseg      |=      |lseg_eq
bool     |lseg      |lseg      |?#     |lseg_intersect
bool     |lseg      |lseg      |?-|    |lseg_perp
bool     |lseg      |lseg      |?||    |lseg_parallel
bool     |money     |money     |<      |cash_lt
bool     |money     |money     |<=     |cash_le
bool     |money     |money     |<>     |cash_ne
bool     |money     |money     |=      |cash_eq
bool     |money     |money     |>      |cash_gt
bool     |money     |money     |>=     |cash_ge
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     |path      |path      |<      |path_n_lt
bool     |path      |path      |<=     |path_n_le
bool     |path      |path      |=      |path_n_eq
bool     |path      |path      |>      |path_n_gt
bool     |path      |path      |>=     |path_n_ge
bool     |path      |path      |?#     |path_inter
bool     |path      |point     |~      |path_contain_pt
bool     |point     |box       |@      |on_pb
bool     |point     |circle    |@      |pt_contained_circle
bool     |point     |line      |@      |on_pl
bool     |point     |lseg      |@      |on_ps
bool     |point     |path      |@      |on_ppath
bool     |point     |path      |@      |pt_contained_path
bool     |point     |point     |<<     |point_left
bool     |point     |point     |<^     |point_below
bool     |point     |point     |>>     |point_right
bool     |point     |point     |>^     |point_above
bool     |point     |point     |?-     |point_horiz
bool     |point     |point     |?|     |point_vert
bool     |point     |point     |~=     |point_eq
bool     |point     |polygon   |@      |pt_contained_poly
bool     |polygon   |point     |~      |poly_contain_pt
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     |timespan  |timespan  |<      |timespan_lt
bool     |timespan  |timespan  |<=     |timespan_le
bool     |timespan  |timespan  |<>     |timespan_ne
bool     |timespan  |timespan  |=      |timespan_eq
bool     |timespan  |timespan  |>      |timespan_gt
bool     |timespan  |timespan  |>=     |timespan_ge
bool     |timestamp |timestamp |<      |timestamplt
bool     |timestamp |timestamp |<=     |timestample
bool     |timestamp |timestamp |<>     |timestampne
bool     |timestamp |timestamp |=      |timestampeq
bool     |timestamp |timestamp |>      |timestampgt
bool     |timestamp |timestamp |>=     |timestampge
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 |<      |intervallt
bool     |tinterval |tinterval |<<     |intervalct
bool     |tinterval |tinterval |<=     |intervalle
bool     |tinterval |tinterval |<>     |intervalne
bool     |tinterval |tinterval |=      |intervaleq
bool     |tinterval |tinterval |>      |intervalgt
bool     |tinterval |tinterval |>=     |intervalge
bool     |tinterval |tinterval |~=     |intervalsame
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
box      |box       |box       |#      |box_intersect
box      |box       |point     |*      |box_mul
box      |box       |point     |+      |box_add
box      |box       |point     |-      |box_sub
box      |box       |point     |/      |box_div
char     |char      |char      |*      |charmul
char     |char      |char      |+      |charpl
char     |char      |char      |-      |charmi
char     |char      |char      |/      |chardiv
circle   |circle    |point     |*      |circle_mul_pt
circle   |circle    |point     |+      |circle_add_pt
circle   |circle    |point     |-      |circle_sub_pt
circle   |circle    |point     |/      |circle_div_pt
date     |date      |int4      |+      |date_pli
date     |date      |int4      |-      |date_mii
datetime |datetime  |timespan  |+      |datetime_pl_span
datetime |datetime  |timespan  |-      |datetime_mi_span
float4   |float4    |float4    |*      |float4mul
float4   |float4    |float4    |+      |float4pl
float4   |float4    |float4    |-      |float4mi
float4   |float4    |float4    |/      |float4div
float8   |box       |box       |<->    |box_distance
float8   |circle    |circle    |<->    |circle_distance
float8   |circle    |polygon   |<->    |dist_cpoly
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
float8   |line      |box       |<->    |dist_lb
float8   |line      |line      |<->    |line_distance
float8   |lseg      |box       |<->    |dist_sb
float8   |lseg      |line      |<->    |dist_sl
float8   |lseg      |lseg      |<->    |lseg_distance
float8   |path      |path      |<->    |path_distance
float8   |point     |box       |<->    |dist_pl
float8   |point     |box       |<->    |dist_pb
float8   |point     |lseg      |<->    |dist_ps
float8   |point     |path      |<->    |dist_ppath
float8   |point     |point     |<->    |point_distance
float8   |polygon   |polygon   |<->    |poly_distance
int2     |int2      |int2      |%      |int2mod
int2     |int2      |int2      |*      |int2mul
int2     |int2      |int2      |+      |int2pl
int2     |int2      |int2      |-      |int2mi
int2     |int2      |int2      |/      |int2div
int4     |date      |date      |-      |date_mi
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
money    |float4    |money     |*      |flt4_mul_cash
money    |float8    |money     |*      |flt8_mul_cash
money    |int2      |money     |*      |int2_mul_cash
money    |int4      |money     |*      |int4_mul_cash
money    |money     |float4    |*      |cash_mul_flt4
money    |money     |float4    |/      |cash_div_flt4
money    |money     |float8    |*      |cash_mul_flt8
money    |money     |float8    |/      |cash_div_flt8
money    |money     |int2      |*      |cash_mul_int2
money    |money     |int2      |/      |cash_div_int2
money    |money     |int4      |*      |cash_mul_int4
money    |money     |int4      |/      |cash_div_int4
money    |money     |money     |+      |cash_pl
money    |money     |money     |-      |cash_mi
path     |path      |path      |+      |path_add
path     |path      |point     |*      |path_mul_pt
path     |path      |point     |+      |path_add_pt
path     |path      |point     |-      |path_sub_pt
path     |path      |point     |/      |path_div_pt
point    |line      |box       |##     |close_lb
point    |lseg      |box       |##     |close_sb
point    |lseg      |line      |##     |close_sl
point    |lseg      |lseg      |#      |lseg_interpt
point    |point     |box       |##     |close_pb
point    |point     |line      |##     |close_pl
point    |point     |lseg      |##     |close_ps
point    |point     |point     |*      |point_mul
point    |point     |point     |+      |point_add
point    |point     |point     |-      |point_sub
point    |point     |point     |/      |point_div
polygon  |point     |circle    |<->    |dist_pc
text     |bpchar    |bpchar    |||     |textcat
text     |text      |text      |||     |textcat
text     |varchar   |varchar   |||     |textcat
timespan |datetime  |datetime  |-      |datetime_mi
timespan |timespan  |timespan  |+      |timespan_pl
timespan |timespan  |timespan  |-      |timespan_mi
timespan |timespan  |timespan  |/      |timespan_div
tinterval|abstime   |abstime   |<#>    |mktinterval
(462 rows)

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,
         t.typname AS operand,
         r.typname AS return_type
FROM     pg_operator o, pg_type t, pg_type r
WHERE    o.oprkind = 'l' AND          -- left unary
         o.oprright = t.oid AND
         o.oprresult = r.oid
ORDER BY operand;
left_unary|operand  |return_type
----------+---------+-----------
@@        |box      |point
@@        |circle   |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
?|        |lseg     |bool
@@        |lseg     |point
?-        |lseg     |bool
??        |path     |float8
#         |path     |int4
@@        |path     |point
@@        |polygon  |point
#         |polygon  |int4
-         |timespan |timespan
|         |tinterval|abstime
(24 rows)

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,
         t.typname AS operand,
         r.typname AS return_type
FROM     pg_operator o, pg_type t, pg_type r
WHERE    o.oprkind = 'r' AND          -- right unary
         o.oprleft = t.oid AND
         o.oprresult = r.oid
ORDER BY operand;
right_unary|operand|return_type
-----------+-------+-----------
%          |float8 |float8
!          |int4   |int4
(2 rows)

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 AS aggname,
         t.typname AS 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
avg    |money
avg    |timespan
max    |abstime
max    |date
max    |datetime
max    |float4
max    |float8
max    |int2
max    |int4
max    |money
max    |timespan
min    |abstime
min    |date
min    |datetime
min    |float4
min    |float8
min    |int2
min    |int4
min    |money
min    |timespan
sum    |float4
sum    |float8
sum    |int2
sum    |int4
sum    |money
sum    |timespan
(30 rows)
count is also available, where count(*) returns a count of all rows while count(column_name) returns a count of all non-null fields in the specified column.

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

BUGS

Although most of the input and output functions corresponding to the base types (e.g., integers and floating point numbers) do some error-checking, some are not particularly rigorous about it. More importantly, few of the operators and functions (e.g., addition and multiplication) perform any error-checking at all. Consequently, many of the numeric operators can (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.