indexed range queries on jsonb?

[Larry White <ljw1001@xxxxxxxxx>]

Hi,

I'm trying to find a way to do a range query on json such that it will use an index. This seems possible given that jsonb supports btrees and _expression_ indices.

For example I have:

create index t1 on document using btree ((payload->'intTest')); 

where: payload is a jsonb column and intTest is a json key whose value is always an int. Based on the documentation examples, I created an index like this:

create index t1 on document using btree ((payload->'intTest'));

Logically, what I want is to be able to make queries like this:

select * from document where ((payload->'intTest'))> 5;

With casting, I came up with:

select * from document where (((payload->'intTest'))::text)::integer > 5;

But this query does not use the index according to Explain

"Seq Scan on public.document  (cost=0.00..1868.33 rows=5764 width=619) (actual time=286.228..1706.638 rows=1974 loops=1)"

"  Output: owner, document_type, guid, schema_version, payload, last_update, payload_class, instance_version, acl_read, deleted, fts_text"

"  Filter: ((((document.payload -> 'intTest'::text))::text)::integer > 5)"

"  Rows Removed by Filter: 15319"

"  Buffers: shared hit=5420 read=29085"

"Planning time: 0.108 ms"

"Execution time: 1706.941 ms"

Any help at all would be appreciated.

Thanks.