Thanks, Gary (and others that responded).    I would absolutely NOT try messing 
with the summary tables; WAY too much “business logic” around those.    It was 
the archive table I was thinking about.  

 

Actually, this thread brings up some thoughts I’ve had for a while (at least 
since starting to use WeeWx). 

 

Before WeeWx, I used some software out of Switzerland (which I can’t quickly 
find, I have archives, but…..) called “meteo” that had what (as a “data guy”) I 
considered to be a “most elegant” database design.   It used a concept of 
“Stations”,  “Sensors” and “observations”, all “normalized”.    The “station” 
table held attributes like the location of the station and so on, for example 
“Prosser, WA, USA, Lat, Long, Elevation, Description, TimeZone”    The “sensor” 
table defined what sensors were available, the units the sensor used, and other 
information relative to that “type” of sensor, for example “Acurite 5n1 Outside 
Temperature, Degrees F, .1 (precision)”.    Each observation was a “time 
series”, for example “StationID, SensorID, timestamp, value”.    Using indexes 
it was really fast to insert new records and to retrieve observations, storage 
required was minimal, and adding a new sensor, or even station, was pretty 
easy.  Reporting was a BIT more “challenging”; but, once the templates were 
right, it wasn’t THAT bad

 

If/when I ever find myself with lots of time and “nothing better to do”; I 
might do the analysis and see what it would take to change the weewx database 
to that sort of schema 

 

From: [email protected] <[email protected]> 
On Behalf Of gjr80
Sent: Thursday, July 16, 2020 8:38 PM
To: weewx-development <[email protected]>
Subject: [weewx-development] Re: Stupid Database Question

 

My advice; by all means restructure your archive table and schema as required 
to suit but don't try manually adjusting the daily summary tables. Far easier 
and safer to use wee_database to drop and then rebuild them - almost certain to 
get yourself tied in knots one way or another otherwise. 300k of records is not 
much and will not take too long at all to rebuild on any half way decent 
machine.

 

Gary

 

On Friday, 17 July 2020 at 09:44:20 UTC+10 [email protected] 
<mailto:[email protected]>  wrote:

Hi!    My day job was (Oracle) DBA for a number of years and I have what’s 
probably a stupid question about modifying the WeeWx database.  

 

Specifically, I want to add some data around solar power generation (watts 
consumed, watts generated, panel efficiency) and possibly rename some of the 
“extraTemp” columns to be more descriptive (like “SolarCollectorTemp”).    I 
get the idea of modifying the schema file and then using wee_database to create 
a new archive table; but, I have over 300K archive records, and that takes a 
while.   Then there’s the whole daily summary process.

 

So – my question is:

Instead of taking weewx down while doing all of the “data movement”, why not:

1.      Change the schema files (for documentation and in case a rebuild IS 
required)
2.      Back up the database, which could be done “live
3.      Use a database ALTER TABLE command to add the column(s) – which could 
be done “live”.
4.      Stop weewx
5.      Do any ALTER TABLEs that might be required to RENAME columns
6.      Add/change “collectors” required for the new/changed columns
7.      Restart weewx

 

Seems to me the only possible downsides to this would be:

1.      Forgetting to change the schema files (“Bad DBA, no cookie!”)
2.      The columns would eventually not be organized alphabetically (but this 
could be fixed by periodically, perhaps once/release, doing the wee_database 
thing.

 

Comments?

 

Clay Jackson

 

 

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