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basic support for multiple_joins_emulation CLICKHOUSE-3996

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This commit is contained in:
chertus 2018-12-27 19:12:42 +03:00
parent 600755745b
commit e8245f5935
4 changed files with 47 additions and 6 deletions
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1
dbms/src/Interpreters/Settings.h
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@ -296,6 +296,7 @@ struct Settings
M(SettingBool, enable_debug_queries, false, "Enables debug queries such as AST.") \
M(SettingBool, enable_unaligned_array_join, false, "Allow ARRAY JOIN with multiple arrays that have different sizes. When this settings is enabled, arrays will be resized to the longest one.") \
M(SettingBool, low_cardinality_allow_in_native_format, true, "Use LowCardinality type in Native format. Otherwise, convert LowCardinality columns to ordinary for select query, and convert ordinary columns to required LowCardinality for insert query.") \
M(SettingBool, allow_experimental_multiple_joins_emulation, false, "Emulate multiple joins using subselects") \
#define DECLARE(TYPE, NAME, DEFAULT, DESCRIPTION) \
TYPE NAME {DEFAULT};

13
dbms/src/Interpreters/executeQuery.cpp
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@ -188,12 +188,13 @@ static std::tuple<ASTPtr, BlockIO> executeQueryImpl(
if (!internal)
logQuery(query.substr(0, settings.log_queries_cut_to_length), context);
#if 1
JoinToSubqueryTransformVisitor::Data join_to_subs_data;
JoinToSubqueryTransformVisitor(join_to_subs_data).visit(ast);
if (join_to_subs_data.done)
logQuery(queryToString(*ast), context);
#endif
if (settings.allow_experimental_multiple_joins_emulation)
{
JoinToSubqueryTransformVisitor::Data join_to_subs_data;
JoinToSubqueryTransformVisitor(join_to_subs_data).visit(ast);
if (join_to_subs_data.done)
logQuery(queryToString(*ast), context);
}
/// Check the limits.
checkASTSizeLimits(*ast, settings);

7
dbms/tests/queries/0_stateless/00820_multiple_joins.reference Normal file
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@ -0,0 +1,7 @@
0 0 0
6 60 600
12 120 1200
18 180 1800
0 0 0
10 100 1000
20 200 2000

32
dbms/tests/queries/0_stateless/00820_multiple_joins.sql Normal file
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@ -0,0 +1,32 @@
USE test;
DROP TABLE IF EXISTS table1;
DROP TABLE IF EXISTS table2;
DROP TABLE IF EXISTS table3;
DROP TABLE IF EXISTS table5;
CREATE TABLE table1 (a UInt32) ENGINE = Memory;
CREATE TABLE table2 (a UInt32, b UInt32) ENGINE = Memory;
CREATE TABLE table3 (b UInt32, c UInt32) ENGINE = Memory;
CREATE TABLE table5 (a UInt32, b UInt32, c UInt32) ENGINE = Memory;
INSERT INTO table1 SELECT number FROM numbers(21);
INSERT INTO table2 SELECT number * 2, number * 20 FROM numbers(11);
INSERT INTO table3 SELECT number * 30, number * 300 FROM numbers(10);
INSERT INTO table5 SELECT number * 5, number * 50, number * 500 FROM numbers(10);
SET allow_experimental_multiple_joins_emulation = 1;
-- FIXME: wrong names qualification
select a, b, c from table1 as t1 join table2 as t2 on t1.a = t2.a join table3 as t3 on b = t3.b;
select a, b, c from table1 as t1 join table2 as t2 on t1.a = t2.a join table5 as t5 on a = t5.a AND b = t5.b;
--select a, b, c, d from table1 as t1 join table2 as t2 on t1.a = t2.a join table3 as t3 on b = t3.b join table5 as t5 on c = t5.c;
--select t1.x, t2.y, t3.z from table1 as t1 join table2 as t2 on t1.x = t2.x join table3 as t3 on t2.y = t3.y;
--select t1.x, t2.y, t3.z from table1 as t1 join (select * from table2 as t2 join table3 as t3 on t2.y = t3.y) on t1.x = t2.x;
--select t1.x, j1.y, j1.z from table1 as t1 join (select * from table2 as t2 join table3 as t3 on t2.y = t3.y) as j1 on t1.x = j1.x;
DROP TABLE table1;
DROP TABLE table2;
DROP TABLE table3;
DROP TABLE table5;