????What are the four broad categories of data quality checks? Provide an implementation technique for each.
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???????????????????ETL?????蟹???????????????????????????妾�
????1????????楗桟orret??
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????2????????楗桿nambiguous??
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????3????????楗桟onsistent??
?????????????????????????????霉?????????????????????????????????'CNY'??
????4????????楗桟omplete??
???????????????????????????????????蔚????????????????????????????????锌??????????????????????????????????????些??????