Variable type Query is only giving time series as the result and not any field

Grafana InfluxDB
1

Grafana Version : 5.1.3
DB : Influx

I have created a dashboard. Now i need to create varibales for the dashboard.

I created one variable of type Data source , It works perfect.
My second variable is of type Query. I am trying to pull certain values from a measurement using a simple select statement. All it returns is time stamp values in microseconds.

Query used : select component_col_name from Tablespace

I am expecting different component_col_name values in the drop down,. but all i get is time values.

My measurement name is Tablespace.

Explain select * from Tablespace
QUERY PLAN
----------
EXPRESSION: <nil>
AUXILIARY FIELDS: App::string, component::string, component_col_name::string, host::string, utilization::float
NUMBER OF SHARDS: 13
NUMBER OF SERIES: 13
CACHED VALUES: 59905
NUMBER OF FILES: 60
NUMBER OF BLOCKS: 1215
SIZE OF BLOCKS: 4782700