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
