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authoryvesf <yvesf-git@xapek.org>2011-07-24 13:12:14 +0200
committeryvesf <yvesf-git@xapek.org>2011-07-24 13:12:14 +0200
commit02f48f7a905973428fc7766cf92bb04614e1fdca (patch)
treed80aa26d4fec9b293ae135c29b10fc071df8ef71 /sql/populate_cache.sql
parent75017423563a18986aa096566d8a2969c32c3588 (diff)
downloadebus-alt-0.3.tar.gz
ebus-alt-0.3.zip
cleanup, tag version 0.3v0.3
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diff --git a/sql/populate_cache.sql b/sql/populate_cache.sql
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+drop table value_cache cascade;
+
+CREATE TABLE value_cache (
+value_real integer,
+timestamp timestamp,
+sensor_id integer
+);
+
+create or replace view vi_value_cache as
+ SELECT timestamp, sensor_id, value_real, 'CACHE'
+ FROM value_cache
+UNION
+ SELECT date_trunc('hour', timestamp), sensor_id, COALESCE(avg(value_int),avg(value_float)), 'LIVE'
+ FROM value
+ WHERE date_trunc('hour', timestamp) > coalesce((select max(timestamp) from value_cache),
+ now() - interval '2 days')
+GROUP BY date_trunc('hour', timestamp), sensor_id;
+;
+
+
+CREATE OR REPLACE FUNCTION value_cache_aktualisieren() RETURNS timestamp AS $value_cache_aktualisieren$
+DECLARE
+ last_update timestamp = now();
+BEGIN
+ select max(date_trunc('hour'::text, "timestamp"))
+ into last_update
+ from value_cache;
+
+ RAISE NOTICE 'last update=%', last_update;
+ if last_update is NULL then
+ last_update = now() - interval '20 days';
+ RAISE NOTICE 'last update set to %', last_update;
+ end if;
+
+ delete from value_cache where timestamp >= last_update;
+
+ insert into value_cache
+ select COALESCE(avg(value_float),avg(value_int)), date_trunc('hour', timestamp), sensor_id
+ from value
+ where date_trunc('hour', timestamp) > last_update
+ group by date_trunc('hour', timestamp), sensor_id;
+
+ RETURN last_update;
+END;
+$value_cache_aktualisieren$ LANGUAGE plpgsql;