--- name: "built-in" section: "3" platform: "linux" package: "postgres95" version: "1.09-1" release: "Debian 1.3 (Bo)" platforms: ["linux"] url: "https://new.carta.tech/built-in" --- # built-in(3) ## 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 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.