Query struct returned from a successfully prepared query. Its fields are:

• name - The name of the prepared statement;
• statement - The prepared statement;
• param_info - List of oids, type info and extension for each parameter;
• param_formats - List of formats for each parameters encoded to;
• encoders - List of anonymous functions to encode each parameter;
• columns - The column names;
• result_info - List of oid, type info and extension for each column;
• result_formats - List of formats for each column is decoded from;
• decoders - List of anonymous functions to decode each column;
• types - The type server table to fetch the type information from;
• null - Atom to use as a stand in for postgres’ NULL;
• copy_data - Whether the query should send the final parameter as data to copy to the database;