You want a table per channel.
If you want to decimate, then use something like (rowid %% %d == 0) where %d is the decimation number of points. The graph display will do bilinear averaging if it's more than the number of pixels it can show so don't bother with that unless you want a specific type of post analysis. Be aware of aliasing though.
The above is a section of code from the following example. You are basically doing a variation of it. It selects a range and displays Decimation number of points from that range but range selection is obtained by zooming on the graph rather than a slider. The query update rate is approximately 100ms and it doesn't change much for even a few million data points in the DB.
It was a few versions ago but I did do some benchmarking of SQLite. So to give you some idea of what effects performance:
Welcome to LavaG.
This is a queue: What Is a Queue in LabVIEW? - NI
You probably tried to delete the control inside the queue indicator. This does not work because a queue must always have a subtype. As the error message suggests, simply drag a new type on the queue indicator and it will replace the existing one.
Alternatively, use the 'Obtain Queue' function on your block diagram to create a new indicator based on the configured input type.
There's a bar I go to by my house that is a bit of a hole in the wall. They have flat panel modern TVs, but the wall mounts for all of them are huge where the CRTs once sat. Its funny to me to see such a thin light TV, sitting on a wall mount that could probably hold 300 pounds.