Small fix in documentation and some examples of usage. Please, apply to

7.3 and current CVS

Oleg Bartunov
This commit is contained in:
Bruce Momjian 2002-12-27 14:10:29 +00:00
parent 9a39ba4b0f
commit 1868b0be44
1 changed files with 39 additions and 2 deletions

View File

@ -8,22 +8,59 @@ signature with length of 4096 bits to represent sets).
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 Oktyabrski has done a great work on
for additional information. Andrey Oktyabrski did 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.
@ -33,7 +70,7 @@ OPERATIONS:
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[] - remove left array from right
int[] - int[] - remove right array from left
int[] | int - returns intarray - union of arguments
int[] | int[] - returns intarray as a union of two arrays
int[] & int[] - returns intersection of arrays