insert:
  foreach new tuple
    insert into table
    insert into udx's -> abort
    insert into sdx

clear:
  clear table
  clear udx's
  clear sdx

remove:
  iterate(delete)

modify:
  iterate(modify)

get:
  findfirst

exists
  findfirst

select:
  interate(copy)

project(cols)
  copy (ignore dups)

project(cols, range)
  iterate(copy)

join:
  find common columns
  join(cols1,cols2)

join:
  writemode?
    -> mergejoin:
      sort tables
      merge
  else
    brute-force

union:
  check compatibility
  copy large table
  copy small table(ignore dups)

intersect
  check compatibility
  iterate over small table:
    copy if tuple exist in large table

difference:
  iterate A:
    copy if not exist in B

count:
  quick query

count(...)
  as select without copy


sort:
  sort
  rebuild idx's