All work was done by Teodor Sigaev (teodor@stack.net) and Oleg Bartunov

(oleg@sai.msu.su). See http://www.sai.msu.su/~megera/postgres/gist

for additional information. Andrey Oktyabrskihas done a great work on

for additional information. Andrey Oktyabrskidid a great work on

adding new functions and operations.

FUNCTIONS:

int icount(int[]) - the number of elements in intarray

test=# select icount('{1,2,3}'::int[]);

icount

--------

3

(1 row)

int[] sort(int[], 'asc' | 'desc') - sort intarray

test=# select sort('{1,2,3}'::int[],'desc');

sort

---------

{3,2,1}

(1 row)

int[] sort(int[]) - sort in ascending order

int[] sort_asc(int[]),sort_desc(int[]) - shortcuts for sort

int[] uniq(int[]) - returns unique elements

test=# select uniq(sort('{1,2,3,2,1}'::int[]));

uniq

---------

{1,2,3}

(1 row)

int idx(int[], int item) - returns index of first intarray matching element to item, or

'0' if matching failed.

test=# select idx('{1,2,3,2,1}'::int[],2);

idx

-----

2

(1 row)

int[] subarray(int[],int START [, int LEN]) - returns part of intarray starting from

element number START (from 1) and length LEN.

test=# select subarray('{1,2,3,2,1}'::int[],2,3);

subarray

----------

{2,3,2}

(1 row)

OPERATIONS:

int[] && int[] - overlap - returns TRUE if arrays has at least one common elements.

int[] + int - push element to array ( add to end of array)

int[] + int[] - merge of arrays (right array added to the end of left one)

int[] - int - remove entries matched by right argument from array

int[] - int[] - removeleft array fromright

int[] - int[] - removeright array fromleft

int[] | int - returns intarray - union of arguments

int[] | int[] - returns intarray as a union of two arrays

int[] & int[] - returns intersection of arrays