BigQuery can be accessed using both GUI and command line. To access BigQuery using a GUI console:

1. Click on the menu button on the top-left corner of the console and select BigQuery from the drop-down menu. You will encounter a new console looking something like this:

2. Click on the COMPOSE QUERY button to enable the text area where queries can be written:

3. To query a public dataset, paste the following text into the text area:

#standardSQL 
SELECT 
 weight_pounds, state, year, gestation_weeks 
FROM 
 `bigquery-public-data.samples.natality` 
ORDER BY weight_pounds DESC LIMIT 10; 

4. Click the RUN QUERY button to run the query and observe the results, which will look like this:

Here as we can see, a public dataset named samples.natality is queried and 3.49 GB of data takes as low as 3.4 seconds to be processed. This speed and simplicity makes BigQuery almost ideal for OLAP.