Suggesting a corrected column name/spelling in the event of a column misspelling

One small PostgreSQL 9.5 feature I worked on is the new hinting mechanism feature, which sometimes hints, based on a score, what you might have meant to type following misspelling a column name in an SQL query. The score heavily weighs Levenshtein distance. A HINT message is sent to the client, which psql and other client tools will display by default.

It's common to not quite recall offhand if a column name is pluralized, or where underscores are used to break up words that make up the name of a column. This feature is targeted at that problem, providing guidance that allows the user to quickly adjust their query without mental context switching. For example:

postgres=# select * from orders where order_id = 5;
ERROR:  42703: column "order_id" does not exist
LINE 1: select * from orders where order_id = 5;
                                   ^
HINT:  Perhaps you meant to reference the column "orders"."orderid".

You may also see a hint in the case of two possible matches, provided both matches have the same score, and the score crosses a certain threshold of assumed usefulness:

postgres=# select * from orders o join orderlines ol on o.orderid = ol.orderid where order_id = 5;

ERROR:  42703: column "order_id" does not exist

LINE 1: ...oin orderlines ol on o.orderid = ol.orderid where order_id =...

                                                             ^

HINT:  Perhaps you meant to reference the column "o"."orderid" or the column "ol"."orderid".

If an alias was used here (which this query must have anyway), the hint becomes more specific:

postgres=# select * from orders o join orderlines ol on o.orderid = ol.orderid where o.order_id = 5;

ERROR:  42703: column o.order_id does not exist

LINE 1: ...oin orderlines ol on o.orderid = ol.orderid where o.order_id...

                                                             ^

HINT:  Perhaps you meant to reference the column "o"."orderid".

This feature should make writing queries interactively in psql a bit more pleasant. Mental context switching to figure these incidental details out has a tendency to slow things down.