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PostgreSQL - Data Types
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  Numeric Types
Name Storage Size Description Range
smallint 2 bytes small-range integer -32768 to +32767
integer 4 bytes ypical choice for integer -2147483648 to +2147483647
bigint 8 bytes large-range integer -9223372036854775808 to +9223372036854775807
decimal variable user-specified precision, exact up to 131072 digits before the decimal point; up to 16383 digits after the decimal point
numeric variable user-specified precision, exact up to 131072 digits before the decimal point; up to 16383 digits after the decimal point
real 4 bytes variable-precision, inexact 6 decimal digits precision
double precision 8 bytes variable-precision, inexact 15 decimal digits precision
smallserial 2 bytes small autoincrementing integer 1 to 32767
serial 4 bytes autoincrementing integer 1 to 2147483647
bigserial 8 bytes large autoincrementing integer 1 to 9223372036854775807
int4range Range of integer
int8range Range of bigint
numrange Range of numeric
  Date/ Time Types
Name Storage Size Description Low Value High Value Resolution
timestamp (without time zone) 8 bytes both date and time (no time zone) 4713 BC 294276 AD 1 microsecond / 14 digits
timestamp (with time zone) 8 bytes both date and time, with time zone 4713 BC 294276 AD 1 microsecond / 14 digits
date 4 bytes date (no time of day) 4713 BC 5874897 AD 1 day
time (without time zone) 8 bytes time of day (no date) 00:00:00 24:00:00 1 microsecond / 14 digits
time (with time zone) 12 bytes times of day only, with time zone 00:00:00+1459 24:00:00-1459 1 microsecond / 14 digits
interval 16 bytes time interval -178000000 years 178000000 years 1 microsecond / 14 digits
tsrange range of timestamp without time zone
tstzrange range of timestamp with time zone
daterange range of date
  Geometric Types
Name Storage Size Description Representation
point 16 bytes Point on a plane (x,y)
line 32 bytes Infinite line {A,B,C}
lseg 32 bytes Finite line segment ((x1,y1),(x2,y2))
box 32 bytes Rectangular box ((x1,y1),(x2,y2))
path 16+16n bytes Closed path (similar to polygon) ((x1,y1),...)
path 16+16n bytes Open path [(x1,y1),...]
polygon 40+16n bytes Polygon (similar to closed path) ((x1,y1),...)
circle 24 bytes Circle <(x,y),r> (center point and radius)
  Network Adress Types
Name Storage Size Description
cidr 7 or 19 bytes IPv4 and IPv6 networks
inet 7 or 19 bytes IPv4 and IPv6 hosts and networks
macaddr 6 bytes MAC addresses
  Character Types
Name Description
character varying(n), varchar(n) variable-length with limit
character(n), char(n) fixed-length, blank padded
text variable unlimited length
  Arrays

In PostgreSQL you can create Arrays of any built-in, user-defined or enum type. In default there is no limit to an Array, but you can specify it.

Declaring an Array

SELECT integer[];
SELECT integer[3];
SELECT integer[][];
SELECT integer[3][3];
SELECT integer ARRAY;
SELECT integer ARRAY[3];

Creating an Array

SELECT '{0,1,2}';
SELECT '{{0,1},{1,2}}';
SELECT ARRAY[0,1,2];
SELECT ARRAY[ARRAY[0,1],ARRAY[1,2]];

Accessing an Array

By default PostgreSQL uses a one-based numbering convention for arrays, that is, an array of n elements starts with array[1] and ends with array[n].

--accesing a spefific element
WITH arr AS (SELECT ARRAY[0,1,2] int_arr) SELECT int_arr[1] FROM arr;

int_arr
---------
        0
(1 row)

--sclicing an array
WITH arr AS (SELECT ARRAY[0,1,2] int_arr) SELECT int_arr[1:2] FROM arr;

int_arr
---------
    {0,1}
(1 row)

Getting information about an array

--array dimensions (as text)
with arr as (select ARRAY[0,1,2] int_arr) select array_dims(int_arr) from arr;

array_dims
------------
       [1:3]
(1 row)

--length of an array dimension
 WITH arr AS (SELECT ARRAY[0,1,2] int_arr) SELECT array_length(int_arr,1) FROM arr;

 array_length
 --------------
              3
 (1 row)

--total number of elements across all dimensions
 WITH arr AS (SELECT ARRAY[0,1,2] int_arr) SELECT cardinality(int_arr) FROM arr;
 
 cardinality
 -------------
             3
 (1 row)

Array functions

will be added

 

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