IoT Time Series Aggregates Service – Selecting¶
Select Syntax¶
With the optional select
parameter one can define which data to return. The value of the select
parameter is a comma separated list of requested data. Each value in the list can either be a variable name or an aggregated field using a variableName.fieldName
syntax. The field name can be one of the following:
countgood
countuncertain
countbad
sum
average
mintime
minvalue
maxtime
maxvalue
firsttime
firstvalue
lasttime
lastvalue
sd
If no select
parameter is specified, all variables and fields are returned. If a variable is specified, but no field name, all the fields for that variable are returned. If a variable and field name are specified, only that field of the variable is returned. Variable names are case-insensitive.
Note
For charting, dashboarding customer should use 'select' for critical fields to be plotted like average, minvalue, maxvalue. This will reduce read size drastically and so read rate. It reduced read rate in tune of 50-70% basis on specific use case.