prefix_match and exact_match

The prefix_match and exact_match predicates are used with Patricia trie indexes. They specify prefixes for string values in a where clause.

For more details on the Patricia trie indexes and search methods, see the Patricia trie Indexes page.

Syntax

select * from ... where s prefix_match '123'

select * from ... where s exact_match '123'     

 

Examples

create table T(s string);
create index idx_s on T(s) using ptree;
insert into T(s) values('123');
insert into T(s) values('12345678');
insert into T(s) values('111222333');

select * from T where s prefix_match '123';
s
------------------------------------------------------------------------------
123
Selected records: 1
					
select * from T where s prefix_match '12345678';
s
------------------------------------------------------------------------------
12345678
123
Selected records: 2
					
select * from T where s exact_match '123';
s
------------------------------------------------------------------------------
123
12345678
Selected records: 2
					
select * from T where s exact_match '12345678';
s
------------------------------------------------------------------------------
12345678
Selected records: 1