Query slow only when using psycopg

[sueskind]

I am using psygopg2 to connect to a TimescaleDB instance. I want to query the latest entries from a big table (35 million rows) containing price information of assets with the columns datetime, asset_id, price, created_at:

create table prices
(
    datetime   timestamptz not null,
    asset_id   integer references assets (asset_id),
    price      real        not null,
    created_at timestamptz not null default now(),

    unique (datetime, asset_id)
);

This table was turned into a TimescaleDB hypertable with

select create_hypertable('"prices"', 'datetime');

and from this article's suggestion created the following index:

create index latest_prices_idx on prices (asset_id, datetime desc);

I use "Option 3" from this article to query the most recent price of each asset:

select distinct on (asset_id) datetime, asset_id, price
from prices
order by asset_id, datetime desc;

which takes ~300ms via my IDE's console. However, when doing the same query via psycopg2 it takes about 10 seconds:

cursor.execute("""
    select distinct on (asset_id) datetime, asset_id, price
    from prices
    order by asset_id, datetime desc;
""")
res = cursor.fetchall()

Why might this be the case?

Edit: Prepending explain in front of the query outputs the exact same result for both the IDE and psycopg.

[sueskind]

The issue was with the IDE I was using (PyCharm). It implicitly limited the query results to 500, but was not showing this in the query logs...