个人代码事项

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  • TODO chrome://gpu
  • TODO Presto aggregate function
    1. count(expression):计算表达式的非空值的数量。如果你不提供任何表达式,它将计算所有行的数量。
    2. sum(expression):计算表达式的总和。
    3. avg(expression):计算表达式的平均值。
    4. min(expression):计算表达式的最小值。
    5. max(expression):计算表达式的最大值。
    6. approx_percentile(expression, percentile):计算表达式的近似百分位数。你需要指定百分位数(介于 0 和 1 之间)。
    7. variance(expression):计算表达式的方差。
    8. stddev(expression):计算表达式的标准差。
    9. histogram(expression):创建一个直方图,显示表达式的值的分布。
    10. array_agg(expression):将表达式的值合并到一个数组中。
    11. map_agg(key_expression, value_expression):创建一个映射,其中每个键都是 key_expression 的唯一值,每个值都是 value_expression 的最后一个非空值。
    12. checksum(expression):计算表达式的校验和。

Usages

Presto aggregate function

SELECT 
    COUNT(t1.latency) AS count0,
    MIN(t1.latency) AS min0, 
    AVG(t1.latency) AS avg0, 
    APPROX_PERCENTILE(t1.latency, 0.5) AS median0,
    APPROX_PERCENTILE(t1.latency, 0.75) AS p75,
    APPROX_PERCENTILE(t1.latency, 0.90) AS p90,
    APPROX_PERCENTILE(t1.latency, 0.99) AS p99,
    APPROX_PERCENTILE(t1.latency, 0.999) AS p999,
    MAX(t1.latency) AS max0, 
    VARIANCE(t1.latency) AS var0,
    STDDEV(t1.latency) AS std0,
    HISTOGRAM(t1.latency) AS h0
FROM dev_shopeepay_qa.shark_tracing_span_log__sg_continuous_s0_test t1 
WHERE t1.dt = '2023-06-11' AND t1.component = 'grpc'