[PERFORM] Unexpected (bad) performance when querying indexed JSONB column

[Christian Weyer]

Hi all,

The pg version in question is the latest 9.4., running on Windows.

For testing out the NoSQL features of pg I have a simple table called 
‘articles’ with a column called ‘data’.

There is an index on ‘data’ like this:
  CREATE INDEX idx_data ON articles USING gin (data jsonb_path_ops);

The current test data set has 32570 entires of JSON docs like this:
{
"title": "Foo Bar",
"locked": true,
"valid_until": "2049-12-31T00:00:00",
"art_number": 12345678,
"valid_since": "2013-10-05T00:00:00",
"number_valid": false,
"combinations": {
"var1": "4711",
"var2": "4711",
"var3": "0815",
"int_art_number": "000001"
}
}

Nothing too complex, I think.

When I run a simple query:
  SELECT data  #>> ‘{"title"}'
  FROM articles
  WHERE data @> '{ “locked" : true }';

Reproducingly, it takes approx. 900ms to get the results back.
Honestly, I was expecting a much faster query.

Any opinions on this?

Thanks,
-C.