Updating metadata

[Rellwood]

Exactly what contributes to taking up time in updating the library metadata?

It seems that it goes about three books per second even when importing a list to update one column with one tag.

If I knew the factors then I could save myself from mass depopulating tags columns and deleting aspects that make no difference, but change the parts that do.

I have a lot of tag rules,

I got rid of a lot of composite columns but there are a few that remain empty and only hold badges from the rules,

I reduced heriarchal shelves.

I have extensive comments in the books.

I have a lot of libraries attached (about 20)

I have a lot of book files (5500)

Any advice or suggestions would be appreciated.