Just like any other index, GIN can be extended. The following strategies are available:
|
Operation |
Strategy number |
|
Overlap |
1 |
|
Contains |
2 |
|
Is contained by |
3 |
|
Equal |
4 |
On top of this, the following support functions are available:
|
Function |
Description |
Support function number |
|
compare |
The compare function is similar to the same function you have seen in b-trees. If two keys are compared, it returns -1 (lower), 0 (equal), or 1 (higher). |
1 |
|
extractValue |
Extract keys from a value to be indexed. A value can have many keys. For example, a text value might consist of more than one word. |
2 |
|
extractQuery |
Extract keys from a query condition. |
3 |
|
consistent |
Check whether a value ... |
