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038235684d
I know at least one way to fool that optimization, by using as sharding key something like `if(col1>0, col1, col2)` (although this is not common sharding key I would say, but can be useful if this will work correctly), so let's disable it by default.
37 lines
1.8 KiB
SQL
37 lines
1.8 KiB
SQL
-- TODO: correct testing with real unique shards
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set optimize_distributed_group_by_sharding_key=1;
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drop table if exists dist_01247;
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drop table if exists dist_layer_01247;
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drop table if exists data_01247;
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create table data_01247 as system.numbers engine=Memory();
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-- since data is not inserted via distributed it will have duplicates
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-- (and this is how we ensure that this optimization will work)
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insert into data_01247 select * from system.numbers limit 2;
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set max_distributed_connections=1;
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set optimize_skip_unused_shards=1;
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select 'Distributed(number)-over-Distributed(number)';
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create table dist_layer_01247 as data_01247 engine=Distributed(test_cluster_two_shards, currentDatabase(), data_01247, number);
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create table dist_01247 as data_01247 engine=Distributed(test_cluster_two_shards, currentDatabase(), dist_layer_01247, number);
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select count(), * from dist_01247 group by number;
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drop table if exists dist_01247;
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drop table if exists dist_layer_01247;
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select 'Distributed(rand)-over-Distributed(number)';
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create table dist_layer_01247 as data_01247 engine=Distributed(test_cluster_two_shards, currentDatabase(), data_01247, number);
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create table dist_01247 as data_01247 engine=Distributed(test_cluster_two_shards, currentDatabase(), dist_layer_01247, rand());
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select count(), * from dist_01247 group by number;
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drop table if exists dist_01247;
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drop table if exists dist_layer_01247;
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select 'Distributed(rand)-over-Distributed(rand)';
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create table dist_layer_01247 as data_01247 engine=Distributed(test_cluster_two_shards, currentDatabase(), data_01247, rand());
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create table dist_01247 as data_01247 engine=Distributed(test_cluster_two_shards, currentDatabase(), dist_layer_01247, number);
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select count(), * from dist_01247 group by number;
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drop table if exists dist_01247;
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drop table if exists dist_layer_01247;
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