Re: [Gnumed-devel] Re: patient search widget timings -more comment

[Horst Herb]

Karsten Hilbert wrote:

> I guess I *must* learn how to do thread-safe update of data
> structures ... Would help a lot for the patient selection
> thing.  Anyone got good pointers for that (not just general
> thread-bla-bla) ?

Just use thread safe message queues both directions instead of directly 
invoking procedures.

However, it should not be neccessary at all:
1.) your "benchmarking" server has specifications way too low to be 
reasonable. While a P133 is certainly good enough, 40 MB of RAM are not. 
128 MB are usually the bare minimum to run any sizeable relational 
database. We might write one day a different ackend for lower-end 
hardware (like using Metakit instead), but for now we focus on Postgres 
and on a server that has a minimum of 128 MB of RAM. bUsing this, you 
will find that tyour reponse times for your queries will drop to maybe 10%

2.) *Don't* try to load a whole patient record at once when a patient 
has been selected. Load what is displayed only, and the rest in the idle 
loop
Algorithm:
-1- load what is visible
-2- start "idle loop loading" one item at a time (not threaded!). Check 
whether item is loaded before loading in idle loop.
-3- "on focus/on visible" events check whether the item to display is 
already loaded, and if not, it does so (should only take a small 
fraction of a second for any one display)

That way, you can always get responsiveness of the user interface (less 
than a second from selecting a patient)

I suggest to use "lazy import" for al notebook widgets for a start.

Horst