Represents key information on an index. An index for index_of is created.
Attribute Name |
Data Type |
Description |
---|---|---|
index_of |
_db_index |
Index to which the key attribute belongs |
key_attr_name |
VARCHAR(255) |
Name of the attribute that comprises the key |
key_order |
INTEGER |
Order of the attribute in the key. Begins with 0. |
asc_desc |
INTEGER |
1 if the order of attribute values is descending, and 0 otherwise. |
key_prefix_length |
INTEGER |
Length of prefix to be used as a key |
The following example shows how to retrieve the names of index that belongs to the class.
SELECT class_of.class_name, SEQUENCE(SELECT key_attr_name
FROM _db_index_key k
WHERE k in i.key_attrs)
FROM _db_index i
WHERE key_count >= 2;
class_of.class_name sequence((select key_attr_name from _db_index_key k where k in
i.key_attrs))
============================================
'_db_partition' {'class_of', 'pname'}
'_db_method' {'class_of', 'meth_name'}
'_db_attribute' {'class_of', 'attr_name'}
'participant' {'host_year', 'nation_code'}
'game' {'host_year', 'event_code', 'athlete_code'}
'record' {'host_year', 'event_code', 'athlete_code', 'medal'}
'history' {'event_code', 'athlete'}