[Xastir-Dev] Short list, stable release, then Xastir-2 development?

[Jerry Chamberlin]

I disagree, make it XASTIR-3 , I never trust an even numbered product.
2.0 is buggy
2.1 they try to fix
2.2 debug code time
2.3 stable

On Thu, 13 Mar 2003, James Jefferson wrote:

> 
> > > My thoughts are that for starters, just the APRS data points received. It
> > > might be helpful to ask Steve Dimse what his database fields are, since
> > > he has plenty of experience in a SQL database of APRS data.
> >
> > We have an Xastir user that has a bit of experience there as well
> > don't we?  James?
> 
> Sure. I'm databasing ~ 2 million packets a day. Running a database with about 
> 60 queries a second 24/7.
> 
> I don't have time today to write too much in depth. But here are the issues I 
> see:
> 
> Indexes, Indexes, Indexes! If you ever do a query that can't take advantage of 
> an index, then the system is as good as dead. With the overhead of the 
> databases and normalization between tables, you're looking about more than a 
> 100 megabytes of data per day. (Heck, the raw stream is at least 50 megabytes 
> a day). If you have to do a table scan off of disk (as is the case with a 
> machine with not a lot of memory) this starts taking real time.
> 
> Figure out what queries you are going to do, and design your tables 
> accordingly. For example, on aprsworld.net there is a lastposition table that 
> is relatively small (<5 megabytes) and then a full position table that has 
> all positions in the database. XAstir would probably want a lastposition 
> table, then another table for all of the positions that need to be shown on 
> screen. 
> 
> Look at the overhead of triggers in Postgres. You may find it nescessary to 
> have the parser / inserter daemon handle triggering. In aprsworld.net's 
> parser it can fork() a program based on the callsign and SSID of the packet 
> it has just inserted. On linux, a signal might be a good way of doing 
> triggers. Dunno about how fast other *nixes handle signals.
> 
> All for now.
> 
> -Jim
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