Indexing a josnb column in postgresql - postgresql

Question

I have a column in postgresql table with type jsonb.
{
.....
"type": "car",
"vehicleIds": [
"980e3761-935a-4e52-be77-9f9461dec4d1","980e3761-935a-4e52-be77-9f9461dec4d2"
]
.....
}
Application runs queries against these fields to fetch records. I need to index this column only for these fields.
How can this be done?
This is query structure with properties as the column name:
SELECT *
FROM Vehicle f
WHERE f.properties::text ## CONCAT('$.vehicleIds[*] >', :vehicleId )= true
AND f.properties::text ## CONCAT('$.type >', :type ) = true

Answer 1

The query you are using is highly confusing, as it boils down to be a text search query, as the ## is applied on a text value.
I also don't understand the '$.type > ... condition. With values like car I would expect an equality operator, rather than "greater than". Using > together with a UUID also doesn't seem to make sense.
If you want to search for values of type car and contain a list of IDs, using the "contains" operator #> is a better way to do that:
SELECT *
FROM Vehicle f
WHERE f.properties #> '{"type": "car", "vehicleIds": ["980e3761-935a-4e52-be77-9f9461dec4d1"]}'
The above could make use of a GIN index on the properties column:
create index on vehicles using gin (properties);
If the type key is always queried with equality (which I assume), a combined index might be more efficient:
create index on vehicles using gin ( (properties ->> 'type'), (properties -> 'vehicleIds') );
You need to install the btree_gin extension in order to create that index.
That index would be a bit smaller but needs a different query:
SELECT *
FROM Vehicle f
WHERE f.properties ->> 'type' = 'car'
AND f.properties -> 'vehicleIds' #> '["980e3761-935a-4e52-be77-9f9461dec4d1"]'
You will need to validate if the indexes are used and which ones is more efficient by looking at the execution plan