Aggregates
Less than 1 minuteAbout 246 words
This chapter mainly introduces the following functions:
| aggregate function | description |
|---|---|
| COUNT() | Returns the number of non-null field values |
| COUNT(time) | the total amount of data by time column |
| MEAN() | Returns the arithmetic average of field values |
| SUM () | Returns the sum of field values. |
| MODE() | Returns the most frequent value in a list of field values |
| STDDEV() | Returns the standard deviation of field values |
| MEDIAN() | Returns the middle value from a sorted list of field values |
| SPREAD() | Returns the difference between the minimum and maximum field values |
| DISTINCT() | Returns the list of unique field values |
| IRATE() | ( |An - An-1| )/( |Tn-1 - Tn| ) |
| RATE() | ( |A1-A2| )/( |T1-T2|) |
| MOVING_AVERAGE() | Returns the rolling average across a window of subsequent field values |
| HOLT_WINTERS() | Returns N number of predicted field values |
| CUMULATIVE_SUM() | Returns the running total of subsequent field values |
| DERIVATIVE() | Returns the rate of change between subsequent field values |
| DIFFERENCE() | Returns the result of subtraction between subsequent field values |
| ELAPSED() | Returns the difference between subsequent field value’s timestamps |
| NON_NEGATIVE_DERIVATIVE() | Returns the non-negative rate of change between subsequent field values |
| NON_NEGATIVE_DIFFERENCE() | Returns the non-negative result of subtraction between subsequent field values |
Tips
The bold part in the list is the unique method of openGemini. Other methods are compatible with the usage of InfluxDB. You can refer to the corresponding function usage of InfluxDB.
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