sql server - Deleting duplicates in a time series -


i have large set of measurements taken every 1 millisecond stored in sql server 2012 table. whenever there 3 or more duplicate values in rows delete middle duplicates. highlighted values in image of sample data ones want delete. there way sql query?

sampledata

you can using cte , row_number:

sql fiddle

with ctegroup as(     select *,         grp = row_number() over(order ms) - row_number() over(partition value order ms)     yourtable ), ctefinal as(     select *,         rn_first = row_number() over(partition grp, value order ms),         rn_last  = row_number() over(partition grp, value order ms desc)     ctegroup ) delete  ctefinal      rn_first > 1     , rn_last > 1

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