timescaledb/tsl/test/sql/cagg_usage.sql
Sven Klemm 5c22ef3da2 Rename continuous aggregate tests
Change the prefix for continuous aggregate tests from
continuous_aggs_ to cagg_. This is similar to commit 6a8c2b66
which did this adjustment for isolation tests because we were
running into length limitations for the spec name. This patch
adjusts the remaining tests to be consistent with the naming
used in isolation tests.
2022-01-24 14:12:56 +01:00

271 lines
9.9 KiB
SQL

-- This file and its contents are licensed under the Timescale License.
-- Please see the included NOTICE for copyright information and
-- LICENSE-TIMESCALE for a copy of the license.
-- TEST SETUP --
\set ON_ERROR_STOP 0
SET client_min_messages TO LOG;
SET work_mem TO '64MB';
-- START OF USAGE TEST --
--First create your hypertable
CREATE TABLE device_readings (
observation_time TIMESTAMPTZ NOT NULL,
device_id TEXT NOT NULL,
metric DOUBLE PRECISION NOT NULL,
PRIMARY KEY(observation_time, device_id)
);
SELECT table_name FROM create_hypertable('device_readings', 'observation_time');
--Next, create your continuous aggregate view
CREATE MATERIALIZED VIEW device_summary
WITH (timescaledb.continuous, timescaledb.materialized_only=true) --This flag is what makes the view continuous
AS
SELECT
time_bucket('1 hour', observation_time) as bucket, --time_bucket is required
device_id,
avg(metric) as metric_avg, --We can use regular aggregates
max(metric)-min(metric) as metric_spread --We can also use expressions on aggregates and constants
FROM
device_readings
GROUP BY bucket, device_id WITH NO DATA; --We have to group by the bucket column, but can also add other group-by columns
SELECT add_continuous_aggregate_policy('device_summary', NULL, '2 h'::interval, '2 h'::interval);
--Next, insert some data into the raw hypertable
INSERT INTO device_readings
SELECT ts, 'device_1', (EXTRACT(EPOCH FROM ts)) from generate_series('2018-12-01 00:00'::timestamp, '2018-12-31 00:00'::timestamp, '30 minutes') ts;
INSERT INTO device_readings
SELECT ts, 'device_2', (EXTRACT(EPOCH FROM ts)) from generate_series('2018-12-01 00:00'::timestamp, '2018-12-31 00:00'::timestamp, '30 minutes') ts;
--Initially, it will be empty.
SELECT * FROM device_summary;
-- Simulate a policy that refreshes with lag, i.e., it doesn't refresh
-- the entire data set. In this case up to the given date.
CALL refresh_continuous_aggregate('device_summary', NULL, '2018-12-30 22:00');
--Now you can run selects over your view as normal
SELECT * FROM device_summary WHERE metric_spread = 1800 ORDER BY bucket DESC, device_id LIMIT 10;
--You can view informaton about your continuous aggregates. The meaning of these fields will be explained further down.
\x
SELECT * FROM timescaledb_information.continuous_aggregates;
\x
-- Refresh interval
--
-- The refresh interval determines how often the background worker
-- for automatic materialization will run. The default is (2 x bucket_width)
SELECT schedule_interval FROM _timescaledb_config.bgw_job WHERE id = 1000;
-- You can change this setting with ALTER VIEW (equivalently, specify in WITH clause of CREATE VIEW)
SELECT alter_job(1000, schedule_interval := '1h');
SELECT schedule_interval FROM _timescaledb_config.bgw_job WHERE id = 1000;
--
-- Refresh with lag
--
-- It is possible to use a policy or manual refresh with a lag, which
-- means the materialization will not contain the most up-to-date
-- data.
SELECT max(observation_time) FROM device_readings;
SELECT max(bucket) FROM device_summary;
CALL refresh_continuous_aggregate('device_summary', NULL, '2018-12-31 01:00');
SELECT max(observation_time) FROM device_readings;
SELECT max(bucket) FROM device_summary;
--
-- Invalidations
--
--Changes to the raw table, for values that have already been materialized are propagated asynchronously, after the materialization next runs.
--Before update:
SELECT * FROM device_summary WHERE device_id = 'device_1' and bucket = 'Sun Dec 30 13:00:00 2018 PST';
INSERT INTO device_readings VALUES ('Sun Dec 30 13:01:00 2018 PST', 'device_1', 1.0);
--Change not reflected before materializer runs.
SELECT * FROM device_summary WHERE device_id = 'device_1' and bucket = 'Sun Dec 30 13:00:00 2018 PST';
CALL refresh_continuous_aggregate('device_summary', NULL, NULL);
--But is reflected after.
SELECT * FROM device_summary WHERE device_id = 'device_1' and bucket = 'Sun Dec 30 13:00:00 2018 PST';
--
-- Dealing with timezones
--
-- You cannot use any functions that depend on the local timezone setting inside a continuous aggregate.
-- For example you cannot cast to the local time. This is because
-- a timezone setting can alter from user-to-user and thus
-- cannot be materialized.
DROP MATERIALIZED VIEW device_summary;
CREATE MATERIALIZED VIEW device_summary
WITH (timescaledb.continuous, timescaledb.materialized_only=true)
AS
SELECT
time_bucket('1 hour', observation_time) as bucket,
min(observation_time::timestamp) as min_time, --note the cast to localtime
device_id,
avg(metric) as metric_avg,
max(metric)-min(metric) as metric_spread
FROM
device_readings
GROUP BY bucket, device_id WITH NO DATA;
--note the error.
-- You have two options:
-- Option 1: be explicit in your timezone:
DROP MATERIALIZED VIEW device_summary;
CREATE MATERIALIZED VIEW device_summary
WITH (timescaledb.continuous, timescaledb.materialized_only=true)
AS
SELECT
time_bucket('1 hour', observation_time) as bucket,
min(observation_time AT TIME ZONE 'EST') as min_time, --note the explict timezone
device_id,
avg(metric) as metric_avg,
max(metric)-min(metric) as metric_spread
FROM
device_readings
GROUP BY bucket, device_id WITH NO DATA;
DROP MATERIALIZED VIEW device_summary;
-- Option 2: Keep things as TIMESTAMPTZ in the view and convert to local time when
-- querying from the view
DROP MATERIALIZED VIEW device_summary;
CREATE MATERIALIZED VIEW device_summary
WITH (timescaledb.continuous, timescaledb.materialized_only=true)
AS
SELECT
time_bucket('1 hour', observation_time) as bucket,
min(observation_time) as min_time, --this is a TIMESTAMPTZ
device_id,
avg(metric) as metric_avg,
max(metric)-min(metric) as metric_spread
FROM
device_readings
GROUP BY bucket, device_id WITH DATA;
SELECT min(min_time)::timestamp FROM device_summary;
--
-- test just in time aggregate / materialization only view
--
-- hardcoding now to 50 will lead to 30 watermark
CREATE OR REPLACE FUNCTION device_readings_int_now()
RETURNS INT LANGUAGE SQL STABLE AS
$BODY$
SELECT 50;
$BODY$;
CREATE TABLE device_readings_int(time int, value float);
SELECT create_hypertable('device_readings_int','time',chunk_time_interval:=10);
SELECT set_integer_now_func('device_readings_int','device_readings_int_now');
CREATE MATERIALIZED VIEW device_readings_mat_only
WITH (timescaledb.continuous, timescaledb.materialized_only=true)
AS
SELECT time_bucket(10,time), avg(value) FROM device_readings_int GROUP BY 1 WITH NO DATA;
CREATE MATERIALIZED VIEW device_readings_jit
WITH (timescaledb.continuous, timescaledb.materialized_only=false)
AS
SELECT time_bucket(10,time), avg(value) FROM device_readings_int GROUP BY 1 WITH NO DATA;
INSERT INTO device_readings_int SELECT i, i*10 FROM generate_series(10,40,10) AS g(i);
-- materialization only should have 0 rows
SELECT * FROM device_readings_mat_only ORDER BY time_bucket;
-- jit aggregate should have 4 rows
SELECT * FROM device_readings_jit ORDER BY time_bucket;
-- simulate a refresh policy with lag, i.e., one that doesn't refresh
-- up to the latest data. Max value is 40.
CALL refresh_continuous_aggregate('device_readings_mat_only', NULL, 30);
CALL refresh_continuous_aggregate('device_readings_jit', NULL, 30);
-- materialization only should have 2 rows
SELECT * FROM device_readings_mat_only ORDER BY time_bucket;
-- jit aggregate should have 4 rows
SELECT * FROM device_readings_jit ORDER BY time_bucket;
-- add 2 more rows
INSERT INTO device_readings_int SELECT i, i*10 FROM generate_series(50,60,10) AS g(i);
-- materialization only should have 2 rows
SELECT * FROM device_readings_mat_only ORDER BY time_bucket;
-- jit aggregate should have 6 rows
SELECT * FROM device_readings_jit ORDER BY time_bucket;
-- hardcoding now to 100 will lead to 80 watermark
CREATE OR REPLACE FUNCTION device_readings_int_now()
RETURNS INT LANGUAGE SQL STABLE AS
$BODY$
SELECT 100;
$BODY$;
-- refresh should materialize all now
CALL refresh_continuous_aggregate('device_readings_mat_only', NULL, NULL);
CALL refresh_continuous_aggregate('device_readings_jit', NULL, NULL);
-- materialization only should have 6 rows
SELECT * FROM device_readings_mat_only ORDER BY time_bucket;
-- jit aggregate should have 6 rows
SELECT * FROM device_readings_jit ORDER BY time_bucket;
-- START OF BASIC USAGE TESTS --
-- Check that continuous aggregate and materialized table is dropped
-- together.
CREATE TABLE whatever(time TIMESTAMPTZ NOT NULL, metric INTEGER);
SELECT * FROM create_hypertable('whatever', 'time');
CREATE MATERIALIZED VIEW whatever_summary WITH (timescaledb.continuous) AS
SELECT time_bucket('1 hour', time) AS bucket, avg(metric)
FROM whatever GROUP BY bucket WITH NO DATA;
SELECT (SELECT format('%1$I.%2$I', schema_name, table_name)::regclass::oid
FROM _timescaledb_catalog.hypertable
WHERE id = raw_hypertable_id) AS raw_table
, (SELECT format('%1$I.%2$I', schema_name, table_name)::regclass::oid
FROM _timescaledb_catalog.hypertable
WHERE id = mat_hypertable_id) AS mat_table
FROM _timescaledb_catalog.continuous_agg
WHERE user_view_name = 'whatever_summary' \gset
SELECT relname FROM pg_class WHERE oid = :mat_table;
----------------------------------------------------------------
-- Should generate an error since the cagg is dependent on the table.
DROP TABLE whatever;
----------------------------------------------------------------
-- Checking that a cagg cannot be dropped if there is a dependent
-- object on it.
CREATE VIEW whatever_summary_dependency AS SELECT * FROM whatever_summary;
-- Should generate an error
DROP MATERIALIZED VIEW whatever_summary;
-- Dropping the dependent view so that we can do a proper drop below.
DROP VIEW whatever_summary_dependency;
----------------------------------------------------------------
-- Dropping the cagg should also remove the materialized table
DROP MATERIALIZED VIEW whatever_summary;
SELECT relname FROM pg_class WHERE oid = :mat_table;
----------------------------------------------------------------
-- Cleanup
DROP TABLE whatever;
-- END OF BASIC USAGE TESTS --