I have always been hesitant to mess with the weeWX DB in case I broke it,
but I ended up modifying the archive table and made a custom schema to
match just in case.

It turned out more fruitful than I expected as I dropped the columns that
were only full of NULLs. Worst case I need to re-add them and then the
NULLs will be re-added too.

The extended schema has some interesting columns, such as 5 regarding hail,
but does anyone know of any hail sensors?

The archive table went from 1.1GB down to 420MB in the process...

The only problem after doing this was weeWX exited on start because I
didn't set a default value on the new columns I added, however after
setting default values weeWX was happy again.

Then I changed the usUnits and interval columns from Int to tiny int, what
that means is instead of MariaDB allocating 4 bytes per value it only uses
1 byte per value. I'm not sure setting those columns as ENUM type would
reduce things further, but the usUnits column only has the number 17 stored
and the interval column is always set to 5...

It was then I noticed that nearly all the columns were of type double,
which seems like over kill to me as most of the time there really is only a
need for 1 decimal place, not 16...

So I altered all the double columns and changed them to floats, since
doubles use 8 bytes per value verses 4 bytes for floats and this again
greatly dropped the table size down to 190MB all up this works out to be
almost 1/10th of it's original size.

At this point I think that's the extent that I can take things and thought
others might like to know that trimming the archive table, without loosing
data, but recover a lot of storage space which will then also speed up
other things like backups and reduce the space needed to store backups.

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