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48 lines
1.4 KiB
Plaintext
48 lines
1.4 KiB
Plaintext
-- { echoOn }
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set allow_experimental_analyzer=1;
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set optimize_trivial_count_query=1;
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create table m3(a Int64, b UInt64) Engine=MergeTree order by tuple();
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select count() from m3;
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0
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insert into m3 values (0,0);
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insert into m3 values (-1,1);
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select trimBoth(explain) from (explain select count() from m3) where explain like '%ReadFromPreparedSource (Optimized trivial count)%';
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ReadFromPreparedSource (Optimized trivial count)
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select count() from m3;
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2
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select count(*) from m3;
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2
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select count(a) from m3;
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2
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select count(b) from m3;
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2
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select count() + 1 from m3;
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3
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drop table m3;
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-- checking queries with FINAL
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create table replacing_m3(a Int64, b UInt64) Engine=ReplacingMergeTree() order by (a, b);
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SYSTEM STOP MERGES replacing_m3;
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select count() from replacing_m3;
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0
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insert into replacing_m3 values (0,0);
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insert into replacing_m3 values (0,0);
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insert into replacing_m3 values (-1,1);
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insert into replacing_m3 values (-2,2);
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select trimBoth(explain) from (explain select count() from replacing_m3) where explain like '%ReadFromPreparedSource (Optimized trivial count)%';
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ReadFromPreparedSource (Optimized trivial count)
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select count() from replacing_m3;
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4
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select count(*) from replacing_m3;
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4
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select count(a) from replacing_m3;
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4
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select count(b) from replacing_m3;
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4
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select count() from replacing_m3 FINAL;
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3
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select count(a) from replacing_m3 FINAL;
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3
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select count(b) from replacing_m3 FINAL;
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3
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drop table replacing_m3;
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