# changes the storagetype of dbmail_headervalue.headervalue to TEXT

# only apply this when dbmail_headervalue.headervalue is VARCHAR(255);

alter table dbmail_headervalue drop index physmessage_id_2;

alter table dbmail_headervalue change headervalue headervalue text not null;

alter table dbmail_headervalue add unique index physmessage_id_2 (physmessage_id, headername_id, headervalue(255));
alter table dbmail_headervalue add index (headervalue(255));