On Thu, 2025-06-19 at 16:50 +1200, Al Grant wrote:
> I want to create a web based dashboard for all the currently detected
> signals, where the dashboard contains a graph of the daily beep rate
> for each channel (max 100 channels) over user selectable periods from
> 1 week to 1 year - that query does not scale well if I query the bpm
> table.
>
> To avoid this I have created a bpm summary table which is generated
> periodically (hourly) off the bpm table. The bpm summary table
> contains the dominant beep rate for a given hour (so 2 records per day
> per channel assuming a signal is detected).
>
> Does this summary table approach make sense?
Yes. Pre-aggregation to reduce the data volume is common in a
data warehouse. Ideally, you don't have to scan the entire base
table to create the summary. You can consider a trigger for that,
but more elegant might be a solution based on partitioning, where
you aggregate a partition once it is complete.
> I have noted that I am periodically syncing from MySQL to the server,
> and then periodically updating the summary table - its multi stage
> syncing and I wonder if that makes this approach fragile (although I
> don't see any alternative).
"MySQL" and "fragile" in the same sentence. Sounds about right.
Yours,
Laurenz Albe
