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ae50a53485
Currently only IMMUTABLE constraints will exclude chunks from an UPDATE plan,
with this patch STABLE expressions will be used to exclude chunks as well.
This is a big performance improvement as chunks not matching partitioning
column constraints don't have to be scanned for UPDATEs.
Since the codepath for UPDATE is different for PG < 14 this patch only adds
the optimization for PG14.
With this patch the plan for UPDATE on hypertables looks like this:
Custom Scan (HypertableModify) (actual rows=0 loops=1)
-> Update on public.metrics_int2 (actual rows=0 loops=1)
Update on public.metrics_int2 metrics_int2_1
Update on _timescaledb_internal._hyper_1_1_chunk metrics_int2
Update on _timescaledb_internal._hyper_1_2_chunk metrics_int2
Update on _timescaledb_internal._hyper_1_3_chunk metrics_int2
-> Custom Scan (ChunkAppend) on public.metrics_int2 (actual rows=0 loops=1)
Output: '123'::text, metrics_int2.tableoid, metrics_int2.ctid
Startup Exclusion: true
Runtime Exclusion: false
Chunks excluded during startup: 3
-> Seq Scan on public.metrics_int2 metrics_int2_1 (actual rows=0 loops=1)
Output: metrics_int2_1.tableoid, metrics_int2_1.ctid
Filter: (metrics_int2_1."time" = length(version()))
82 lines
4.0 KiB
PL/PgSQL
82 lines
4.0 KiB
PL/PgSQL
-- This file and its contents are licensed under the Timescale License.
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-- Please see the included NOTICE for copyright information and
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-- LICENSE-TIMESCALE for a copy of the license.
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CREATE TABLE metrics_int2(c1 int,c2 int, c3 int, c4 int, c5 int, time int2 NOT NULL, value float, data text);
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CREATE TABLE metrics_int4(c1 int,c2 int, c3 int, c4 int, c5 int, time int4 NOT NULL, value float, data text);
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CREATE TABLE metrics_int8(c1 int,c2 int, c3 int, c4 int, c5 int, time int8 NOT NULL, value float, data text);
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CREATE TABLE metrics_date(c1 int,c2 int, c3 int, c4 int, c5 int, time date NOT NULL, value float, data text);
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CREATE TABLE metrics_timestamp(c1 int,c2 int, c3 int, c4 int, c5 int, time timestamp NOT NULL, value float, data text);
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CREATE TABLE metrics_timestamptz(c1 int,c2 int, c3 int, c4 int, c5 int, time timestamptz NOT NULL, value float, data text);
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CREATE TABLE metrics_space(c1 int,c2 int, c3 int, c4 int, c5 int, time timestamp NOT NULL, device text, value float, data text);
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SELECT table_name FROM create_hypertable('metrics_int2','time',chunk_time_interval:=10);
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SELECT table_name FROM create_hypertable('metrics_int4','time',chunk_time_interval:=10);
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SELECT table_name FROM create_hypertable('metrics_int8','time',chunk_time_interval:=10);
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SELECT table_name FROM create_hypertable('metrics_date','time');
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SELECT table_name FROM create_hypertable('metrics_timestamp','time');
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SELECT table_name FROM create_hypertable('metrics_timestamptz','time');
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SELECT table_name FROM create_hypertable('metrics_space','time','device',4);
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CREATE FUNCTION drop_column(text) RETURNS VOID LANGUAGE PLPGSQL AS $$
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DECLARE
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tbl name;
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BEGIN
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FOR tbl IN SELECT 'metrics_' || unnest(ARRAY['int2','int4','int8','date','timestamp','timestamptz','space'])
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LOOP
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EXECUTE format('ALTER TABLE %I DROP COLUMN %I;', tbl, $1);
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END LOOP;
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END;
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$$;
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-- create 4 chunks each with different physical layout
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SELECT drop_column('c1');
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INSERT INTO metrics_int2(time) VALUES (0);
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INSERT INTO metrics_int4(time) VALUES (0);
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INSERT INTO metrics_int8(time) VALUES (0);
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INSERT INTO metrics_date(time) VALUES ('2000-01-01');
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INSERT INTO metrics_timestamp(time) VALUES ('2000-01-01');
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INSERT INTO metrics_timestamptz(time) VALUES ('2000-01-01');
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INSERT INTO metrics_space(time,device) VALUES ('2000-01-01','1'),('2000-01-01','2');
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SELECT drop_column('c2');
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INSERT INTO metrics_int2(time) VALUES (10);
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INSERT INTO metrics_int4(time) VALUES (10);
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INSERT INTO metrics_int8(time) VALUES (10);
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INSERT INTO metrics_date(time) VALUES ('2001-01-01');
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INSERT INTO metrics_timestamp(time) VALUES ('2001-01-01');
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INSERT INTO metrics_timestamptz(time) VALUES ('2001-01-01');
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INSERT INTO metrics_space(time,device) VALUES ('2001-01-01','1'),('2001-01-01','2');
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SELECT drop_column('c3');
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INSERT INTO metrics_int2(time) VALUES (20);
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INSERT INTO metrics_int4(time) VALUES (20);
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INSERT INTO metrics_int8(time) VALUES (20);
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INSERT INTO metrics_date(time) VALUES ('2002-01-01');
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INSERT INTO metrics_timestamp(time) VALUES ('2002-01-01');
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INSERT INTO metrics_timestamptz(time) VALUES ('2002-01-01');
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INSERT INTO metrics_space(time,device) VALUES ('2002-01-01','1'),('2002-01-01','2');
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SELECT drop_column('c4');
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INSERT INTO metrics_int2(time) VALUES (30);
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INSERT INTO metrics_int4(time) VALUES (30);
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INSERT INTO metrics_int8(time) VALUES (30);
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INSERT INTO metrics_date(time) VALUES ('2003-01-01');
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INSERT INTO metrics_timestamp(time) VALUES ('2003-01-01');
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INSERT INTO metrics_timestamptz(time) VALUES ('2003-01-01');
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INSERT INTO metrics_space(time,device) VALUES ('2003-01-01','1'),('2003-01-01','2');
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SELECT drop_column('c5');
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CREATE TABLE metrics_compressed(time timestamptz NOT NULL, device int, value float);
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SELECT table_name FROM create_hypertable('metrics_compressed','time');
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ALTER TABLE metrics_compressed SET (timescaledb.compress);
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-- create first chunk and compress
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INSERT INTO metrics_compressed VALUES ('2000-01-01',1,0.5);
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SELECT count(compress_chunk(chunk)) FROM show_chunks('metrics_compressed') chunk;
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-- create more chunks
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INSERT INTO metrics_compressed VALUES ('2010-01-01',1,0.5),('2011-01-01',1,0.5),('2012-01-01',1,0.5);
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