When you create a new questionnaire, if you give it a long name e.g. "a really long title that apparently witll make the system crash if we keep going beyond about 55 characters apparently" then you get the following error

Debug info: ERROR: value too long for type character varying(64)
INSERT INTO lab_questionnaire_survey (owner,name,realm,title,subtitle,email,theme,thanks_page,thank_head,thank_body,info) VALUES($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11) RETURNING id
[array (
'owner' => '64',
'name' => 'a really long title that apparently witll make the system crash if we keep going beyond about 55 characters apparently',
'realm' => 'private',
'title' => 'a really long title that apparently witll make the system crash if we keep going beyond about 55 characters apparently',
'subtitle' => '',
'email' => '',
'theme' => '',
'thanks_page' => '',
'thank_head' => '',
'thank_body' => '',
'info' => '',
)]
Error code: dmlwriteexception
Stack trace:

line 410 of /lib/dml/moodle_database.php: dml_write_exception thrown
line 239 of /lib/dml/pgsql_native_moodle_database.php: call to moodle_database->query_end()
line 823 of /lib/dml/pgsql_native_moodle_database.php: call to pgsql_native_moodle_database->query_end()
line 875 of /lib/dml/pgsql_native_moodle_database.php: call to pgsql_native_moodle_database->insert_record_raw()
line 927 of /mod/questionnaire/locallib.php: call to pgsql_native_moodle_database->insert_record()
line 131 of /mod/questionnaire/lib.php: call to questionnaire->survey_update()
line 458 of /course/modedit.php: call to questionnaire_add_instance()

Apparently, if you give the questionnaire a really short name, then save it and go back and change the name, everything is fine.