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authorBruce Momjian2002-12-27 14:10:29 +0000
committerBruce Momjian2002-12-27 14:10:29 +0000
commit1868b0be44e44f7c03516559625a966176af5f83 (patch)
tree5dc495f71a3e79ad820001de190b89d23906bf9d
parent9a39ba4b0fe6dc6b3744b31bc5115837b88677ae (diff)
Small fix in documentation and some examples of usage. Please, apply to
7.3 and current CVS Oleg Bartunov
-rw-r--r--contrib/intarray/README.intarray41
1 files changed, 39 insertions, 2 deletions
diff --git a/contrib/intarray/README.intarray b/contrib/intarray/README.intarray
index 6c8bc13e17..a1ffef1e4a 100644
--- a/contrib/intarray/README.intarray
+++ b/contrib/intarray/README.intarray
@@ -8,22 +8,59 @@ signature with length of 4096 bits to represent sets).
All work was done by Teodor Sigaev ([email protected]) and Oleg Bartunov
([email protected]). 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