mirror of
https://github.com/timescale/timescaledb.git
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273 lines
7.2 KiB
PL/PgSQL
273 lines
7.2 KiB
PL/PgSQL
-- This file and its contents are licensed under the Apache License 2.0.
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-- Please see the included NOTICE for copyright information and
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-- LICENSE-APACHE for a copy of the license.
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\set PREFIX 'EXPLAIN (VERBOSE, COSTS OFF)'
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-- Create a two dimensional hypertable
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CREATE TABLE hyper (time timestamptz, device int, temp float);
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SELECT * FROM create_hypertable('hyper', 'time', 'device', 2);
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-- Create a similar PostgreSQL partitioned table
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CREATE TABLE pg2dim (time timestamptz, device int, temp float) PARTITION BY HASH (device);
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CREATE TABLE pg2dim_h1 PARTITION OF pg2dim FOR VALUES WITH (MODULUS 2, REMAINDER 0) PARTITION BY RANGE(time);
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CREATE TABLE pg2dim_h2 PARTITION OF pg2dim FOR VALUES WITH (MODULUS 2, REMAINDER 1) PARTITION BY RANGE(time);
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CREATE TABLE pg2dim_h1_t1 PARTITION OF pg2dim_h1 FOR VALUES FROM ('2018-01-01 00:00') TO ('2018-09-01 00:00');
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CREATE TABLE pg2dim_h1_t2 PARTITION OF pg2dim_h1 FOR VALUES FROM ('2018-09-01 00:00') TO ('2018-12-01 00:00');
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CREATE TABLE pg2dim_h2_t1 PARTITION OF pg2dim_h2 FOR VALUES FROM ('2018-01-01 00:00') TO ('2018-09-01 00:00');
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CREATE TABLE pg2dim_h2_t2 PARTITION OF pg2dim_h2 FOR VALUES FROM ('2018-09-01 00:00') TO ('2018-12-01 00:00');
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-- Create a 1-dimensional partitioned table for comparison
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CREATE TABLE pg1dim (time timestamptz, device int, temp float) PARTITION BY HASH (device);
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CREATE TABLE pg1dim_h1 PARTITION OF pg1dim FOR VALUES WITH (MODULUS 2, REMAINDER 0);
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CREATE TABLE pg1dim_h2 PARTITION OF pg1dim FOR VALUES WITH (MODULUS 2, REMAINDER 1);
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INSERT INTO hyper VALUES
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('2018-02-19 13:01', 1, 2.3),
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('2018-02-19 13:02', 3, 3.1),
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('2018-10-19 13:01', 1, 7.6),
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('2018-10-19 13:02', 3, 9.0);
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INSERT INTO pg2dim VALUES
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('2018-02-19 13:01', 1, 2.3),
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('2018-02-19 13:02', 3, 3.1),
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('2018-10-19 13:01', 1, 7.6),
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('2018-10-19 13:02', 3, 9.0);
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INSERT INTO pg1dim VALUES
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('2018-02-19 13:01', 1, 2.3),
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('2018-02-19 13:02', 3, 3.1),
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('2018-10-19 13:01', 1, 7.6),
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('2018-10-19 13:02', 3, 9.0);
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SELECT * FROM test.show_subtables('hyper');
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SELECT * FROM pg2dim_h1_t1;
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SELECT * FROM pg2dim_h1_t2;
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SELECT * FROM pg2dim_h2_t1;
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SELECT * FROM pg2dim_h2_t2;
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-- Compare partitionwise aggreate enabled/disabled. First run queries
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-- on PG partitioned tables for reference.
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-- All partition keys covered by GROUP BY
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SET enable_partitionwise_aggregate = 'off';
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:PREFIX
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SELECT device, avg(temp)
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FROM pg1dim
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GROUP BY 1
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ORDER BY 1;
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SET enable_partitionwise_aggregate = 'on';
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:PREFIX
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SELECT device, avg(temp)
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FROM pg1dim
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GROUP BY 1
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ORDER BY 1;
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-- All partition keys not covered by GROUP BY (partial partitionwise)
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SET enable_partitionwise_aggregate = 'off';
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:PREFIX
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SELECT device, avg(temp)
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FROM pg2dim
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GROUP BY 1
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ORDER BY 1;
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SET enable_partitionwise_aggregate = 'on';
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:PREFIX
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SELECT device, avg(temp)
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FROM pg2dim
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GROUP BY 1
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ORDER BY 1;
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-- All partition keys covered by GROUP BY (full partitionwise)
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SET enable_partitionwise_aggregate = 'off';
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:PREFIX
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SELECT time, device, avg(temp)
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FROM pg2dim
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GROUP BY 1, 2
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ORDER BY 1, 2;
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SET enable_partitionwise_aggregate = 'on';
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:PREFIX
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SELECT time, device, avg(temp)
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FROM pg2dim
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GROUP BY 1, 2
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ORDER BY 1, 2;
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-- All partition keys not covered by GROUP BY because of date_trunc
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-- expression on time (partial partitionwise)
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SET enable_partitionwise_aggregate = 'off';
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:PREFIX
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SELECT date_trunc('month', time), device, avg(temp)
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FROM pg2dim
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GROUP BY 1, 2
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ORDER BY 1, 2;
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SET enable_partitionwise_aggregate = 'on';
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:PREFIX
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SELECT date_trunc('month', time), device, avg(temp)
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FROM pg2dim
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GROUP BY 1, 2
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ORDER BY 1, 2;
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-- Now run on hypertable
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-- All partition keys not covered by GROUP BY (partial partitionwise)
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SET enable_partitionwise_aggregate = 'off';
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:PREFIX
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SELECT device, avg(temp)
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FROM hyper
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GROUP BY 1
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ORDER BY 1;
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SET enable_partitionwise_aggregate = 'on';
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:PREFIX
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SELECT device, avg(temp)
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FROM hyper
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GROUP BY 1
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ORDER BY 1;
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-- All partition keys covered (full partitionwise)
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SET enable_partitionwise_aggregate = 'off';
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:PREFIX
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SELECT time, device, avg(temp)
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FROM hyper
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GROUP BY 1, 2
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ORDER BY 1, 2;
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SET enable_partitionwise_aggregate = 'on';
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:PREFIX
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SELECT time, device, avg(temp)
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FROM hyper
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GROUP BY 1, 2
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ORDER BY 1, 2;
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-- Partial aggregation since date_trunc(time) is not a partition key
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SET enable_partitionwise_aggregate = 'off';
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:PREFIX
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SELECT date_trunc('month', time), device, avg(temp)
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FROM hyper
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GROUP BY 1, 2
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ORDER BY 1, 2;
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SET enable_partitionwise_aggregate = 'on';
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:PREFIX
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SELECT date_trunc('month', time), device, avg(temp)
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FROM hyper
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GROUP BY 1, 2
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ORDER BY 1, 2;
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-- Also test time_bucket
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SET enable_partitionwise_aggregate = 'off';
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:PREFIX
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SELECT time_bucket('1 month', time), device, avg(temp)
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FROM hyper
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GROUP BY 1, 2
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ORDER BY 1, 2;
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SET enable_partitionwise_aggregate = 'on';
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:PREFIX
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SELECT time_bucket('1 month', time), device, avg(temp)
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FROM hyper
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GROUP BY 1, 2
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ORDER BY 1, 2;
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-- Test partitionwise joins, mostly to see that we do not break
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-- anything
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CREATE TABLE hyper_meta (time timestamptz, device int, info text);
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SELECT * FROM create_hypertable('hyper_meta', 'time', 'device', 2);
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INSERT INTO hyper_meta VALUES
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('2018-02-19 13:01', 1, 'device_1'),
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('2018-02-19 13:02', 3, 'device_3');
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SET enable_partitionwise_join = 'off';
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:PREFIX
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SELECT h.time, h.device, h.temp, hm.info
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FROM hyper h, hyper_meta hm
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WHERE h.device = hm.device;
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:PREFIX
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SELECT pg2.time, pg2.device, pg2.temp, pg1.temp
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FROM pg2dim pg2, pg1dim pg1
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WHERE pg2.device = pg1.device;
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SET enable_partitionwise_join = 'on';
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:PREFIX
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SELECT h.time, h.device, h.temp, hm.info
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FROM hyper h, hyper_meta hm
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WHERE h.device = hm.device;
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:PREFIX
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SELECT pg2.time, pg2.device, pg2.temp, pg1.temp
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FROM pg2dim pg2, pg1dim pg1
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WHERE pg2.device = pg1.device;
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-- Test hypertable with time partitioning function
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CREATE OR REPLACE FUNCTION time_func(unixtime float8)
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RETURNS TIMESTAMPTZ LANGUAGE PLPGSQL IMMUTABLE AS
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$BODY$
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DECLARE
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retval TIMESTAMPTZ;
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BEGIN
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retval := to_timestamp(unixtime);
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RETURN retval;
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END
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$BODY$;
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CREATE TABLE hyper_timepart (time float8, device int, temp float);
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SELECT * FROM create_hypertable('hyper_timepart', 'time', 'device', 2, time_partitioning_func => 'time_func');
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-- Planner won't pick push-down aggs on table with time function
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-- unless a certain amount of data
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SELECT setseed(1);
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INSERT INTO hyper_timepart
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SELECT x, ceil(random() * 8), random() * 20
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FROM generate_series(0,5000-1) AS x;
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-- All partition keys covered (full partitionwise)
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SET enable_partitionwise_aggregate = 'off';
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:PREFIX
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SELECT time, device, avg(temp)
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FROM hyper_timepart
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GROUP BY 1, 2
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ORDER BY 1, 2
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LIMIT 10;
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:PREFIX
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SELECT time_func(time), device, avg(temp)
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FROM hyper_timepart
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GROUP BY 1, 2
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ORDER BY 1, 2
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LIMIT 10;
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-- Grouping on original time column should be pushed-down
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SET enable_partitionwise_aggregate = 'on';
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:PREFIX
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SELECT time, device, avg(temp)
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FROM hyper_timepart
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GROUP BY 1, 2
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ORDER BY 1, 2
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LIMIT 10;
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-- Applying the time partitioning function should also allow push-down
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-- on open dimensions
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:PREFIX
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SELECT time_func(time), device, avg(temp)
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FROM hyper_timepart
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GROUP BY 1, 2
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ORDER BY 1, 2
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LIMIT 10;
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-- Should also work to use partitioning function on closed dimensions
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:PREFIX
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SELECT time_func(time), _timescaledb_internal.get_partition_hash(device), avg(temp)
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FROM hyper_timepart
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GROUP BY 1, 2
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ORDER BY 1, 2
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LIMIT 10;
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