Disclosure control rules

This section is relevant only to microdata-based datasets.

Cantabular can apply disclosure control rules to microdata-based datasets that prevent the publication of overly disclosive tables. These rules are specified in the disclosure rules language (DRL). See “Disclosure Rules Language” in product documentation for full details.

The example microdata dataset has a simple rule for demonstration purposes. It prevents the publication of tables containing more than 41 cells. This will prohibit a query containing City (3 categories), Sex (2 categories) and Number of siblings (7 categories) as the output table would contain 42 cells.

example/src/microdata/example-rules.txt:

querytest main()
  // Prevent query with City (3 categories), Sex (2 categories) and
  // Number of siblings (7 categories) which would have 42 cells.
  fail "MAX_CELLS" if not withinMaxCells(41)
end

querytest withinMaxCells(max)
  var numCells = 1
  for v in query.vars
    numCells *= (len v.cats)
  end
  fail if numCells > max
end