Jd/Ops drop

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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' 


drops each col of each table
releases lock
deletes filefolder



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 [/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)