Aggregate Functions
Aggregate functions perform a calculation on a set of values and return a single value.
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COUNT(expression)
COUNT(*)Return the number of rows. When expression is specified, the count returned will be the number of matched rows. When * is specified, the count returned will be the total number of rows.
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AVG(expression)Return the average value of a given expression.
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SUM(expression)Return the sum value of a given expression.
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MAX(expression)Return the max value of a given expression.
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MIN(expression)Return the min value of a given expression.
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TOPK(expression_value, expression_k)Return the top K(specified by expression_k) values of expression_value in a array.
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TOPKDISTINCT(expression_value, expression_k)Similar to TOPK, but only returns distinct values of expression_value.