Untitled query #51330

SQL

use hrwiki_p;
# 20050101   4874  132
# 20060101  11961   56
# 20070101  25894   64
# 20080101  40636  101
# 20090101  56647  113
# 20100101  79730  150
# 20110101  97987  208
# 20120101 111734  269
# 20130101 127553  308
# 20140101 142457  343
# 20150101 150179  572
# 20160101 160411  751
# 20170101 171474  910
# 20180101 181338 1049
# 20190101 201325 1168
# 20200101 213332 1200
# 20200201 214537 1177
# 20200301 215377 1133
# 20200401 216302 1109
# 20200501 217404 1096
# 20200601 218314 1107
# 20200701 219405 1102
# 20200801 220348 1112
# 20200901 221362 1109
# 20201001 222356 1119
# 20201101 223036 1134
# 20201201 223962 1144
# 20210101 224502 1142


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 '20210114', 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 
  group by pa.page_id
  
  ORDER BY YEAR(r.rev_timestamp)
SQL

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