On 08/15/2013 08:07 AM, Ivan Radovanovic wrote:
> On 08/15/13 16:59, Adrian Klaver napisa:
>> On 08/15/2013 07:53 AM, Ivan Radovanovic wrote:
>>
>>>>>
>>>>> Now I just need to find out which types can be indexed (and which
>>>>> types
>>>>> can be part of PK)
>>>>
>>>> http://www.postgresql.org/docs/9.2/interactive/indexes.html
>>>>
>>>
>>> doesn't list which types can be indexed and which can't?
>>
>> Postgres can handle a variety of indexes including indexing on
>> expressions, which is why I pointed you to that link.
>>
>> To cut to the chase, in the above link at:
>>
>> http://www.postgresql.org/docs/9.2/interactive/indexes-opclass.html
>>
>> there is this:
>>
>> SELECT am.amname AS index_method,
>> opf.opfname AS opfamily_name,
>> amop.amopopr::regoperator AS opfamily_operator
>> FROM pg_am am, pg_opfamily opf, pg_amop amop
>> WHERE opf.opfmethod = am.oid AND
>> amop.amopfamily = opf.oid
>> ORDER BY index_method, opfamily_name, opfamily_operator;
>>>
>>>
>
> Thanks Adrian, but question was how to decide which types are indexable
> - query which you sent returns list of operators defined for some types
> - for example it returns operators for bytea too, and you can't index by
> bytea,
Actually you can:
CREATE TABLE bytea_test(id int, fld_1 bytea);
test=# \d bytea_test
Table "public.bytea_test"
Column | Type | Modifiers
--------+---------+-----------
id | integer |
fld_1 | bytea |
test=# CREATE INDEX i ON bytea_test (fld_1);
test=# \d bytea_test
Table "public.bytea_test"
Column | Type | Modifiers
--------+---------+-----------
id | integer |
fld_1 | bytea |
Indexes:
"i" btree (fld_1)
--
Adrian Klaver
adrian.klaver@gmail.com
