admin/master_files display is VERY slow to load

[sdm7g]

From looking at the logs, 2/3 or more of the overhead appears to be from these two MySQL queries,
which are used in the column headers:

(47046.9ms) SELECT COUNT() FROM master_files WHERE master_files.type = 'Tiff'
(22881.9ms) SELECT COUNT() FROM master_files WHERE master_files.type = 'JpegTwoThousand'

If there isn't a way to effectively cache these queries, maybe we can just eliminate them from the display but keep them as search options. They are always showing 0 JP2K master files anyway -- Can that even be correct ?

On further investigation, it turns out that those counts for JP2Ks are incorrect, because the type fields for those JP2k MasterFiles is incorrectly = nil.

I suggest that we turn off those two scope fields in production, since they are not currently working correctly and produce a lot of overhead, and look at both correcting them and fixing performance later.

for example, see:
https://tracksys.lib.virginia.edu/admin/master_files?q%5Bunit_id_eq%5D=28951

[sdm7g]

We did remove those fields, at least for now, and performance is much improved.

[sdm7g]

Provisionally closing for now, but we need to look further at optimizations. In general, many pages load too slowly.