问题
I created a materialized view in Postgres 9.3 but I have since lost the underlying SELECT query that created it. I would like to DROP the materialized view, rewrite the query to include more data, and then CREATE a materialized view of the same name but with a new underlying query.
回答1:
Just:
SELECT pg_get_viewdef('myview');
from the client of your choice.
e.g. in psql
:
test=> CREATE MATERIALIZED VIEW fred AS SELECT x FROM generate_series(1,100) x;
SELECT 100
test=> \a\t
Output format is unaligned.
Showing only tuples.
test=> SELECT pg_get_viewdef('fred');
SELECT x.x
FROM generate_series(1, 100) x(x);
This works for normal and materialized views.
Alternately, as Richard says, use psql
's \d+
, which calls pg_get_viewdef
behind the scenes.
回答2:
SELECT * FROM "pg_catalog"."pg_matviews"
That's how you find a list of all the materialized views you created. I'd never used or seen the pg_catalog schema before and Navicat, the GUI I use, was hiding "system items" that included pg_catalog. You can turn turn hiding off in the app's preferences.
来源:https://stackoverflow.com/questions/25737315/how-do-i-discover-the-underlying-query-of-a-materialized-view-i-created