Untitled query #51476

SQL

use tewiki_p;
# 20050101   4874  132
# 20060101  11961   56
# 20070101  25894   64
# 20080101  40636  101
# 20090101  
# 20100101  
# 20110101  
# 20120101 
# 20130101 
# 20140101 
# 20150101 
# 20160101 
# 20170101 
# 20180101 	63257	1610
# 20190101 	65591	1272
# 20200101	68241 	1001
# 20210101	70246 	378

select count(*), round(avg(age)) as avg_age
from (
  select pa.page_id, 
  str_to_date(max(r.rev_timestamp), '%Y%m%d') as ts, 
  datediff(date '20210101', str_to_date(max(r.rev_timestamp), '%Y%m%d')) - 1 as age
  from page pa 
  inner join revision r on r.rev_page = pa.page_id
  where pa.page_namespace in (0, 102) and pa.page_is_redirect = 0 and
  r.rev_timestamp < '20170101'
  group by pa.page_id
) t
SQL

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