void ensureColumnExists(String column, String columnType) throws SqlException {
            if (columnNames().contains(column)) return;
            issueAsync("alter table " + name + " add column " + column + " " + columnType, newContext());
        }
Repairs this db on corruption.

@param e the exception indicating corruption
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/QuestMetricsDb.java