Hola Lista Tiempo sin hablarmos!! :-)
Estaba leyendo el siguiente articulo: https://www.cybertec-postgresql.com/en/advanced-sql-why-first_value-and-last_value-are-no-bugs/ y de este genere la siguiente consulta SELECT *, array_agg(x) OVER () as todos, array_agg(x) OVER (ORDER BY x) as order_asc, array_agg(x) OVER (ORDER BY x DESC) as order_desc, last_value(x) OVER (ORDER BY x) FROM generate_series(1, 5) AS x order by 1; cuyos resultados son: x | todos | order_asc | order_desc | last_value ---+-------------+-------------+-------------+------------ 1 | {1,2,3,4,5} | {1} | {5,4,3,2,1} | 1 2 | {1,2,3,4,5} | {1,2} | {5,4,3,2} | 2 3 | {1,2,3,4,5} | {1,2,3} | {5,4,3} | 3 4 | {1,2,3,4,5} | {1,2,3,4} | {5,4} | 4 5 | {1,2,3,4,5} | {1,2,3,4,5} | {5} | 5 (5 rows) Y la verdad no entiendo la lógica del 'filtrado' que hace el order by (ASC/DESC). Gracias Lista -- Cordialmente, Ing. Hellmuth I. Vargas S.
