Can we use query while retrieving the data from the dataset in AWS IoT Analytics, I want data between 2 timestamps. Im using boto3 to fetch the data. I didn't see any option to use query in get dataset content Below is the boto3 code:
response = client.get_dataset_content(
datasetName='string',
versionId='string'
)
Does anyone have suggestions how to use query or how rerieve the data between 2 timestamp in AWS IoT Analytics?
Thanks, Pankaj
There could be a few ways to do this depending on what your workflow is, if you have a few more details, that would be helpful.
Possible approaches are;
1) Create a scheduled query to run every hour (for example) where the query looks something like this;
SELECT * FROM my_datastore WHERE __dt >= current_date - interval '1' day
AND my_timestamp >= now() - interval '1' hour
You may need to adjust the format of the timestamp to suit depending on how you are storing it (epoch seconds, epoch milliseconds, ISO8601 etc. If you set this to run every hour, each time it executes, you will get the last one hour of data. Note that the __dt constraint just helps your query run faster (and cheaper) by limiting the scan to the most recent day only.
2) You can improve on the above by using the delta window function of the dataset which lets you get the data that has arrived since the query last ran more easily. You could then simplify your query to look like;
select * from my_datastore where __dt >= current_date - interval '1' day
And configure the delta time window to look at your timestamp field. You then control how much data is retrieved by the frequency at which you execute the query (every 15 mins, every hour etc).
3) If you have a more general purpose requirement to fetch the data between 2 timestamps that you are calculating programatically, and may not be of the form now() - some interval, the way you could do this is to create a dataset and then update the dataset with the revised SQL expression before running it with create-dataset-content. That way the dataset content is updated with just the results you need with each execution. If this is of interest, I can expand upon the actual python required.
4) As Thomas suggested, it can often be just as easy to pull out a larger chunk of data with the dataset (for example the last day) and then filter down to the timestamp you want in code. This is particularly easy if you are using panda dataframes for example and there are plenty of related questions such as this one that have good answers.
Frankly, the easiest thing would be to do your own time filtering (the result of get_dataset_content is a csv file).
That's what QuickSight does to allow you to navigate the dataset in time.
If this isn't feasible the alternative is to reprocess the datastore with an updated pipeline that filters out everything except the time range you're interested in (more information here). You should note that while it's tempting to use the startTime and endTime parameters for StartPipelineReprocessing, these are only approximate to the nearest hour.
