I was going to add just one field to the database, I would repurpose an existing field that is unused but has a similar unit. If you're going do more than 5 fields, then doing your own db may be the better way. If you're writing a single value every 15 min, I wouldn't worry about performance/locking issues.
On Mon, Sep 11, 2023 at 10:57 AM DR <wxe...@gmail.com> wrote: > Thank you for not only the information, but the link to learn more. I > appreciate that. > > Since this group lives and breathes solutions, I'm curious as to the > comment that my approach (as you can tell, a very inexperienced programmer) > was the best way. > > The only other thought I would have would be to create my own little > SQLite data base (one filed other than the date and time) and have WeeWx > use that new database as a second source of information, rather than try to > just stuff one more new field in the schema. Does someone have a more > reasonable and sensible approach than what I suggested? Just a key word or > two for me to go looking would be helpful. Dale > > > On 9/11/2023 10:59 AM, Tom Keffer wrote: > > I'm not sure your approach is the best one, but to answer your questions: > > 1. Yes, WeeWX opens the database and leaves it open. > 2. Contention is managed by the SQLite database. See this documentation > <https://sqlite.org/lockingv3.html>. > 3. Unless an extension is acting otherwise, WeeWX does not write with > every LOOP packet. Only when archive records arrive. > > On Mon, Sep 11, 2023 at 8:10 AM DR <wxe...@gmail.com> wrote: > >> I'm just thinking about another project, and wonder how WeeWx uses the >> default database. >> >> >> When it is running does it open and leave open the database all the time? >> >> If so, is the database able to have another program add records to the >> database while WeeWx has it open? >> >> The reason I ask, is that I would like to have another program running >> which reads snow depth from a Campbell Scientific table, then add that >> value to the standard database at say 15 minute intervals with a field >> defined and added to the schema. >> >> In some days past, I know some databases would prevent more than one >> attempt to access it, even if not in the traditional deadly embrace >> situation. >> >> If WeeWx is busy stuffing new values in every 2 seconds during loop >> functions, can I also access it simultaneously as long as I don't try to >> touch the fields that WeeWx is writing to? >> >> >> Or is it necessary to shut down, briefly, access, then have the snow >> depth program open it, write the value, close it and then let WeeWx go >> merrily on it's way? >> >> I hope this question is within the scope of this user discussion. Dale >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "weewx-user" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to weewx-user+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/weewx-user/918b02a3-72d7-f7f7-2e77-a3a374489a85%40gmail.com >> . >> > -- > You received this message because you are subscribed to the Google Groups > "weewx-user" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to weewx-user+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/weewx-user/CAPq0zEAjUcruwXiaeAkFhUY3mJEaFUbT%2Bh_SB8CL28xTyMFH%2BA%40mail.gmail.com > <https://groups.google.com/d/msgid/weewx-user/CAPq0zEAjUcruwXiaeAkFhUY3mJEaFUbT%2Bh_SB8CL28xTyMFH%2BA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "weewx-user" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to weewx-user+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/weewx-user/12538f08-287f-b3a5-3c8b-28c15486910c%40gmail.com > <https://groups.google.com/d/msgid/weewx-user/12538f08-287f-b3a5-3c8b-28c15486910c%40gmail.com?utm_medium=email&utm_source=footer> > . > -- Peter Quinn (415)794-2264 -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/CAA1SM21fe3ruZaeaE9RW81Bz5rcXB8qKzA_KQX8QzRuQcpRPCw%40mail.gmail.com.
