IoT Time Series Aggregates Service – Selecting¶
Select Syntax¶
With the optional select
parameter, it is possible to 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. It reduces read rate in tune of 50-70% basis on specific use case.