Small fix in documentation and some examples of usage. Please, apply to
7.3 and current CVS Oleg Bartunov
This commit is contained in:
parent
9a39ba4b0f
commit
1868b0be44
1 changed files with 39 additions and 2 deletions
|
@ -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
|
||||
|
|
Loading…
Reference in a new issue