mirror of https://github.com/citusdata/citus.git
141 lines
6.1 KiB
Plaintext
141 lines
6.1 KiB
Plaintext
--
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-- MULTI_FUNCTION_EVALUATION
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--
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SET citus.next_shard_id TO 1200000;
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-- nextval() works (no good way to test DEFAULT, or, by extension, SERIAL)
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CREATE TABLE example (key INT, value INT);
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SELECT master_create_distributed_table('example', 'key', 'hash');
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master_create_distributed_table
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---------------------------------
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(1 row)
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CREATE SEQUENCE example_value_seq;
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SELECT master_create_worker_shards('example', 1, 2);
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master_create_worker_shards
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-----------------------------
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(1 row)
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INSERT INTO example VALUES (1, nextval('example_value_seq'));
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SELECT * FROM example;
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key | value
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-----+-------
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1 | 1
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(1 row)
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-- functions called by prepared statements are also evaluated
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PREPARE stmt AS INSERT INTO example VALUES (2);
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EXECUTE stmt;
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EXECUTE stmt;
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SELECT * FROM example;
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key | value
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-----+-------
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1 | 1
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2 |
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2 |
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(3 rows)
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-- non-immutable functions inside CASE/COALESCE aren't allowed
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ALTER TABLE example DROP value;
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NOTICE: using one-phase commit for distributed DDL commands
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HINT: You can enable two-phase commit for extra safety with: SET citus.multi_shard_commit_protocol TO '2pc'
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ALTER TABLE example ADD value timestamp;
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-- this is allowed because there are no mutable funcs in the CASE
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UPDATE example SET value = (CASE WHEN value > timestamp '12-12-1991' THEN timestamp '12-12-1991' ELSE value + interval '1 hour' END) WHERE key = 1;
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-- this is allowed because the planner strips away the CASE during constant evaluation
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UPDATE example SET value = CASE WHEN true THEN now() ELSE now() + interval '1 hour' END WHERE key = 1;
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-- this is not allowed because there're mutable functions in a CaseWhen clause
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-- (which we can't easily evaluate on the master)
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UPDATE example SET value = (CASE WHEN now() > timestamp '12-12-1991' THEN now() ELSE timestamp '10-24-1190' END) WHERE key = 1;
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ERROR: non-IMMUTABLE functions are not allowed in CASE or COALESCE statements
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-- make sure we also check defresult (the ELSE clause)
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UPDATE example SET value = (CASE WHEN now() > timestamp '12-12-1991' THEN timestamp '12-12-1191' ELSE now() END) WHERE key = 1;
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ERROR: non-IMMUTABLE functions are not allowed in CASE or COALESCE statements
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-- COALESCE is allowed
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UPDATE example SET value = COALESCE(null, null, timestamp '10-10-1000') WHERE key = 1;
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-- COALESCE is not allowed if there are any mutable functions
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UPDATE example SET value = COALESCE(now(), timestamp '10-10-1000') WHERE key = 1;
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ERROR: non-IMMUTABLE functions are not allowed in CASE or COALESCE statements
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UPDATE example SET value = COALESCE(timestamp '10-10-1000', now()) WHERE key = 1;
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ERROR: non-IMMUTABLE functions are not allowed in CASE or COALESCE statements
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-- RowCompareExpr's are checked for mutability. These are allowed:
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ALTER TABLE example DROP value;
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ALTER TABLE example ADD value boolean;
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ALTER TABLE example ADD time_col timestamptz;
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UPDATE example SET value = NULLIF(ROW(1, 2) < ROW(2, 3), true) WHERE key = 1;
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UPDATE example SET value = NULLIF(ROW(true, 2) < ROW(value, 3), true) WHERE key = 1;
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-- But this RowCompareExpr is not (it passes Var into STABLE)
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UPDATE example SET value = NULLIF(
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ROW(date '10-10-1000', 2) < ROW(time_col, 3), true
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) WHERE key = 1;
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ERROR: STABLE functions used in UPDATE queries cannot be called with column references
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-- DistinctExpr's are also checked for mutability. These are allowed:
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UPDATE example SET value = 1 IS DISTINCT FROM 2 WHERE key = 1;
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UPDATE example SET value = date '10-10-1000' IS DISTINCT FROM timestamptz '10-10-1000' WHERE key = 1;
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-- But this RowCompare references the STABLE = (date, timestamptz) operator
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UPDATE example SET value = date '10-10-1000' IS DISTINCT FROM time_col WHERE key = 1;
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ERROR: STABLE functions used in UPDATE queries cannot be called with column references
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-- this ScalarArrayOpExpr ("scalar op ANY/ALL (array)") is allowed
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UPDATE example SET value = date '10-10-1000' = ANY ('{10-10-1000}'::date[]) WHERE key = 1;
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-- this ScalarArrayOpExpr is not, it invokes the STABLE = (timestamptz, date) operator
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UPDATE example SET value = time_col = ANY ('{10-10-1000}'::date[]) WHERE key = 1;
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ERROR: STABLE functions used in UPDATE queries cannot be called with column references
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-- CoerceViaIO (typoutput -> typinput, a type coercion)
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ALTER TABLE example DROP value;
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ALTER TABLE example ADD value date;
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-- this one is allowed
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UPDATE example SET value = (timestamp '10-19-2000 13:29')::date WHERE key = 1;
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-- this one is not
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UPDATE example SET value = time_col::date WHERE key = 1;
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ERROR: STABLE functions used in UPDATE queries cannot be called with column references
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-- ArrayCoerceExpr (applies elemfuncid to each elem)
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ALTER TABLE example DROP value;
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ALTER TABLE example ADD value date[];
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-- this one is allowed
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UPDATE example SET value = array[timestamptz '10-20-2013 10:20']::date[] WHERE key = 1;
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-- this one is not
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UPDATE example SET value = array[time_col]::date[] WHERE key = 1;
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ERROR: STABLE functions used in UPDATE queries cannot be called with column references
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-- test that UPDATE and DELETE also have the functions in WHERE evaluated
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ALTER TABLE example DROP time_col;
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ALTER TABLE example DROP value;
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ALTER TABLE example ADD value timestamptz;
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INSERT INTO example VALUES (3, now());
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UPDATE example SET value = timestamp '10-10-2000 00:00' WHERE key = 3 AND value > now() - interval '1 hour';
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SELECT * FROM example WHERE key = 3;
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key | value
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-----+------------------------------
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3 | Tue Oct 10 00:00:00 2000 PDT
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(1 row)
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DELETE FROM example WHERE key = 3 AND value < now() - interval '1 hour';
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SELECT * FROM example WHERE key = 3;
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key | value
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-----+-------
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(0 rows)
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-- test that function evaluation descends into expressions
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CREATE OR REPLACE FUNCTION stable_fn()
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RETURNS timestamptz STABLE
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LANGUAGE plpgsql
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AS $function$
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BEGIN
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RAISE NOTICE 'stable_fn called';
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RETURN timestamp '10-10-2000 00:00';
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END;
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$function$;
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INSERT INTO example VALUES (44, (ARRAY[stable_fn(),stable_fn()])[1]);
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NOTICE: stable_fn called
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CONTEXT: PL/pgSQL function stable_fn() line 3 at RAISE
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NOTICE: stable_fn called
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CONTEXT: PL/pgSQL function stable_fn() line 3 at RAISE
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SELECT * FROM example WHERE key = 44;
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key | value
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-----+------------------------------
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44 | Tue Oct 10 00:00:00 2000 PDT
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(1 row)
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DROP FUNCTION stable_fn();
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DROP TABLE example;
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