Comparison predicates with row value constructors about order_query HOT 1 OPEN

Hi!

Besides the row values, there is also a performance problem with the logic as shown in the README:

x0 OR 
y0 AND (x1 OR
        y1 AND (x2 OR
                y2 AND ...))

The problem is that this kind of where-clause cannot use and index on these columns, even if it exists. No matter which database.

See here: http://use-the-index-luke.com/sql/partial-results/fetch-next-page#sb-equivalent-logic

To use an index, you must not have an OR on the top level comparison.

Let me know if you have any questions.

-Markus Winand

from order_query.