I am loading a bunch of data into a PostgresQL 9.3 database and then I want to refresh all materialized views that depend on the updated tables. Is there a way to do it automatically instead of going through each view and refreshing them one by one? I know that Oracle can do that rather easily but I did not find anything after combing through PostgreSQL documentation.
Looks like current version of PostgreSQL (9.3.1) does not have such functionality, have had to write my own function instead:
CREATE OR REPLACE FUNCTION RefreshAllMaterializedViews(schema_arg TEXT DEFAULT 'public')
RETURNS INT AS $$
DECLARE
r RECORD;
BEGIN
RAISE NOTICE 'Refreshing materialized view in schema %', schema_arg;
FOR r IN SELECT matviewname FROM pg_matviews WHERE schemaname = schema_arg
LOOP
RAISE NOTICE 'Refreshing %.%', schema_arg, r.matviewname;
EXECUTE 'REFRESH MATERIALIZED VIEW ' || schema_arg || '.' || r.matviewname;
END LOOP;
RETURN 1;
END
$$ LANGUAGE plpgsql;
(on github: https://github.com/sorokine/RefreshAllMaterializedViews)
The above answers work fine if the materialized views do not depend on each other. If that is not the case, then the order in which the materialized views are refreshed is important (i.e., you need to refresh the materialized views that don't depend on any other materialized views before you refresh those that do). The code below will generate an ordered list of materialized views so that they can be updated in the correct order.
CREATE OR REPLACE VIEW mat_view_dependencies AS
WITH RECURSIVE s(start_schemaname,start_mvname,schemaname,mvname,relkind,
mvoid,depth) AS (
-- List of mat views -- with no dependencies
SELECT n.nspname AS start_schemaname, c.relname AS start_mvname,
n.nspname AS schemaname, c.relname AS mvname, c.relkind,
c.oid AS mvoid, 0 AS depth
FROM pg_class c JOIN pg_namespace n ON c.relnamespace=n.oid
WHERE c.relkind='m'
UNION
-- Recursively find all things depending on previous level
SELECT s.start_schemaname, s.start_mvname,
n.nspname AS schemaname, c.relname AS mvname,
c.relkind,
c.oid AS mvoid, depth+1 AS depth
FROM s
JOIN pg_depend d ON s.mvoid=d.refobjid
JOIN pg_rewrite r ON d.objid=r.oid
JOIN pg_class c ON r.ev_class=c.oid AND (c.relkind IN ('m','v'))
JOIN pg_namespace n ON n.oid=c.relnamespace
WHERE s.mvoid <> c.oid -- exclude the current MV which always depends on itself
)
SELECT * FROM s;
CREATE OR REPLACE VIEW mat_view_refresh_order AS
WITH b AS (
-- Select the highest depth of each mat view name
SELECT DISTINCT ON (schemaname,mvname) schemaname, mvname, depth
FROM mat_view_dependencies
WHERE relkind='m'
ORDER BY schemaname, mvname, depth DESC
)
-- Reorder appropriately
SELECT schemaname, mvname, depth AS refresh_order
FROM b
ORDER BY depth, schemaname, mvname
;
This can be used in psql
to refresh all views in the appropriate order as follows:
WITH a AS (
SELECT 'REFRESH MATERIALIZED VIEW "' || schemaname || '"."' || mvname || '";' AS r
FROM mat_view_refresh_order
ORDER BY refresh_order
)
SELECT string_agg(r,E'\n') AS script FROM a \gset
\echo :script
:script
This final part can, alternatively, be converted into a function as has been done in the previous solutions.
same method, added the option to run it on all schema's, optionally concurrently.
CREATE OR REPLACE FUNCTION RefreshAllMaterializedViews(_schema TEXT DEFAULT '*', _concurrently BOOLEAN DEFAULT false)
RETURNS INT AS $$
DECLARE
r RECORD;
BEGIN
RAISE NOTICE 'Refreshing materialized view(s) in % %', CASE WHEN _schema = '*' THEN ' all schemas' ELSE 'schema "'|| _schema || '"' END, CASE WHEN _concurrently THEN 'concurrently' ELSE '' END;
IF pg_is_in_recovery() THEN
RETURN 0;
ELSE
FOR r IN SELECT schemaname, matviewname FROM pg_matviews WHERE schemaname = _schema OR _schema = '*'
LOOP
RAISE NOTICE 'Refreshing %.%', r.schemaname, r.matviewname;
EXECUTE 'REFRESH MATERIALIZED VIEW ' || CASE WHEN _concurrently THEN 'CONCURRENTLY ' ELSE '' END || '"' || r.schemaname || '"."' || r.matviewname || '"';
END LOOP;
END IF;
RETURN 1;
END
$$ LANGUAGE plpgsql;
I also put it on GitHub: https://github.com/frankhommers/RefreshAllMaterializedViews
same method, added standby check
CREATE OR REPLACE FUNCTION RefreshAllMaterializedViews(schema_arg TEXT DEFAULT 'public')
RETURNS INT AS $$
DECLARE
r RECORD;
BEGIN
RAISE NOTICE 'Refreshing materialized view in schema %', schema_arg;
if pg_is_in_recovery() then
return 1;
else
FOR r IN SELECT matviewname FROM pg_matviews WHERE schemaname = schema_arg
LOOP
RAISE NOTICE 'Refreshing %.%', schema_arg, r.matviewname;
EXECUTE 'REFRESH MATERIALIZED VIEW ' || schema_arg || '.' || r.matviewname;
END LOOP;
end if;
RETURN 1;
END
$$ LANGUAGE plpgsql;
The snippet below uses REFRESH MATERIALIZED VIEW CONCURRENTLY
when a UNIQUE
index exists for that view.
CREATE OR REPLACE FUNCTION public.refresh_materialized_views()
RETURNS void
AS
$BODY$
DECLARE
refresh_sql text;
BEGIN
WITH matviews AS (
SELECT t.oid,
relname AS view_name,
nspname AS schema_name
FROM pg_class t
JOIN pg_catalog.pg_namespace n ON n.oid = t.relnamespace
WHERE t.relkind = 'm'
AND nspname NOT LIKE 'pg-%'
), unique_indexes AS (
SELECT m.oid,
view_name,
schema_name
FROM pg_class i,
pg_index ix,
matviews m
WHERE ix.indisunique = true
AND ix.indexrelid = i.oid
AND ix.indrelid = m.oid
), refresh_concurrently AS (
SELECT 'REFRESH MATERIALIZED VIEW CONCURRENTLY ' || quote_ident(schema_name) || '.' || quote_ident(view_name) AS sql
FROM unique_indexes
), refresh AS (
SELECT 'REFRESH MATERIALIZED VIEW ' || quote_ident(schema_name) || '.' || quote_ident(view_name) AS sql
FROM matviews
WHERE oid != all (SELECT oid FROM unique_indexes)
), sql AS (
SELECT sql FROM refresh_concurrently
UNION ALL
SELECT sql FROM refresh
)
SELECT string_agg(sql, E';\n') || E';\n' FROM sql INTO refresh_sql;
EXECUTE refresh_sql;
END;
$BODY$
LANGUAGE plpgsql VOLATILE;
This snippet accepts a schema name to limit the views that are refreshed.
CREATE OR REPLACE FUNCTION public.refresh_materialized_views(_schema text)
RETURNS void
AS
$BODY$
DECLARE
refresh_sql text;
BEGIN
WITH matviews AS (
SELECT t.oid,
relname AS view_name,
nspname AS schema_name
FROM pg_class t
JOIN pg_catalog.pg_namespace n ON n.oid = t.relnamespace
WHERE t.relkind = 'm'
AND nspname NOT LIKE 'pg-%'
AND nspname = _schema
), unique_indexes AS (
SELECT m.oid,
view_name,
schema_name
FROM pg_class i,
pg_index ix,
matviews m
WHERE ix.indisunique = true
AND ix.indexrelid = i.oid
AND ix.indrelid = m.oid
), refresh_concurrently AS (
SELECT 'REFRESH MATERIALIZED VIEW CONCURRENTLY ' || quote_ident(schema_name) || '.' || quote_ident(view_name) AS sql
FROM unique_indexes
), refresh AS (
SELECT 'REFRESH MATERIALIZED VIEW ' || quote_ident(schema_name) || '.' || quote_ident(view_name) AS sql
FROM matviews
WHERE oid != all (SELECT oid FROM unique_indexes)
), sql AS (
SELECT sql FROM refresh_concurrently
UNION ALL
SELECT sql FROM refresh
)
SELECT string_agg(sql, E';\n') || E';\n' FROM sql INTO refresh_sql;
EXECUTE refresh_sql;
END;
$BODY$
LANGUAGE plpgsql VOLATILE;
来源:https://stackoverflow.com/questions/19981600/how-to-refresh-all-materialized-views-in-postgresql-9-3-at-once