Sample.sql

--Syntax (version 1.0)

--Unconditional sampling, single sample rate
select * from sample(
   ON ...
  SAMPLEFRACTION('fraction')
  [Seed('seed')]
  
--Unconditional sampling, total approximate sample size
select * from sample (
  ON ... as data PARTITION BY ANY 
  ON ... as summary DIMENSION
  ApproximateSampleSize('size')
  [Seed('seed')]
  
--conditional simple sampling, single sample rate
select * from sample (
   ON ...
  CONDITIONONCOLUMN('column')
  CONDITIONON('cond1'[,'cond2',...])
  SAMPLEFRACTION('fraction')
  [SEED('seed')]
  
--Conditional sampling, variable sample rates
select * from sample (
   ON ...
  CONDITIONONCOLUMN('column')
  CONDITIONON('cond1'[,'cond2',...])
  SAMPLEFRACTION('f1'[,'f2','f3',...])
  [SEED('seed')]
  
--Conditional sampling, total approximate sample size
select * from sample (
  ON ... as data PARTITION BY ANY
  ON ... as summary DIMENSION 
  CONDITIONONCOLUMN('column')
  CONDITIONON('cond1'[,'cond2',...])
  ApproximateSampleSize('total_sample_size')
  [SEED('seed')]
  
--Conditional sampling, variable approximate sample sizes
select * from sample (
  ON ... as data PARTITION BY ANY
  ON ... as summary DIMENSION 
  CONDITIONONCOLUMN('column')
  CONDITIONON('cond1'[,'cond2',...])
  APPROXIMATESAMPLESIZE('s1'[,'s2',...])
  [SEED('seed')]