Jd/Ops drop

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dropcol

dropcol table col
OK if col does not exist
error if col is used in a ref

drop a ref col by name as you would any other col
get ref col names with:

jd'info ref' 

dropdb

drops each col of each table
releases lock
deletes filefolder

dropfilesize

dropfilesize

files tend to be kept larger than required
data in the file can grow without having to resize/remap

dropfilesize frees up unused file space - use if a db is static

dropfilesize returns filenames, old size, new size

droptable

droptable [/reset] table

/reset preserves schema
  drops rows
  drops dynamic hash/unique/... cols
  keeps filesize

OK if table does not exist
error if table has reference (refers to or referred by)