Total Sessions in BigQuery vs Google Analytics Reports

Question

I\'m just learning BigQuery so this might be a dumb question, but we want to get some statistics there and one of those is the total sessions in a given day.

To do s

Answer 1

The problem could be due to "COUNT DISTINCT".

According to this post:

COUNT DISTINCT is a statistical approximation for all results greater than 1000

You could try setting an additional COUNT parameter to improve accuracy at the expense of performance (see post), but I would first try:

SELECT COUNT( CONCAT( fullvisitorid,'_', STRING(visitid))) as sessions 
from (table_query([40663402], 'timestamp(right(table_id,8)) between 
timestamp("20150519") and timestamp("20150519")'))