How to use large SQL-query for %{sql:} clause?

Hello. I am using FR v2.1.6. I am needing to generate values of reply attributes via SQL. I am using `%{sql:SQL-query}` clause. I am inserting attribute/value pairs into radreply table, where value - `%{sql:}`-clause. But I had got complex and large queries. I don't want to increase size of fields of SQL-table. How I can solve this problem?