在发布问题后，我们与Google支持部门联系并发现，在Google Analytics中，只有发生事件的会话才算实际计数。

在Bigquery中，您会发现所有会话，无论它们是否有交互。

为了找到与GA相同的结果，您应该过滤在您的BQ查询（ totals.visits ）中，通过与 totals.visits = 1 进行的会话仅在会话中有1

即：

  select sum（ （table_query（[40663402]，'timestamp（right（table_id，8））中的total_sessions作为会话，
选择
 fullvisitorid，
 count（distinct visitid） ）在时间戳（20150519）和时间戳（20150519）之间））
其中totals.visits = 1 
每组通过fullvisitorid 
）
 

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 so, I've queried in BQ:

select sum(sessions) as total_sessions from (
  select
    fullvisitorid,
    count(distinct visitid) as sessions,
    from (table_query([40663402], 'timestamp(right(table_id,8)) between timestamp("20150519") and timestamp("20150519")'))
    group each by fullvisitorid
)

(I'm using the table_query because later on we might increase the range of days)

This results in 1,075,137.

But in our Google Analytics Reports, in the "Audience Overview" section, the same day results:

This report is based on 1,026,641 sessions (100% of sessions).

There's always this difference of roughly ~5% despite of the day. So I'm wondering, even though the query is quite simple, is there any mistake we've made?

Is this difference expected to happen? I read through BigQuery's documentation but couldn't find anything on this issue.

Thanks in advance,

After posting the question we got into contact with Google support and found that in Google Analytics only sessions that had an "event" being fired are actually counted.

In Bigquery you will find all sessions regardless whether they had an interaction or not.

In order to find the same result as in GA, you should filter by sessions with totals.visits = 1 in your BQ query (totals.visits is 1 only for sessions that had an event being fired).

That is:

select sum(sessions) as total_sessions from (
  select
    fullvisitorid,
    count(distinct visitid) as sessions,
    from (table_query([40663402], 'timestamp(right(table_id,8)) between timestamp("20150519") and timestamp("20150519")'))
    where totals.visits = 1
    group each by fullvisitorid
)