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Fixed error with StorageMerge [#CLICKHOUSE-2].

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This commit is contained in:
Alexey Milovidov 2018-02-21 23:24:29 +03:00
parent 222fb2c945
commit 02f7cc2d04
3 changed files with 3029 additions and 1 deletions
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12
dbms/src/Storages/StorageMerge.cpp
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@ -192,7 +192,7 @@ BlockInputStreams StorageMerge::read(
if (real_column_names.size() == 0)
real_column_names.push_back(ExpressionActions::getSmallestColumn(table->getColumnsList()));
/// Substitute virtual column for its value. NOTE This looks terribly wrong.
/// Substitute virtual column for its value when querying tables.
ASTPtr modified_query_ast = query->clone();
VirtualColumnUtils::rewriteEntityInAst(modified_query_ast, "_table", table->getTableName());
@ -220,6 +220,12 @@ BlockInputStreams StorageMerge::read(
throw Exception("Source tables for Merge table are processing data up to different stages",
ErrorCodes::INCOMPATIBLE_SOURCE_TABLES);
/// The table may return excessive columns if we query only its virtual column.
/// We filter excessive columns. This is done only if query was not processed more than FetchColumns.
if (processed_stage_in_source_table == QueryProcessingStage::FetchColumns)
for (auto & stream : source_streams)
stream = std::make_shared<FilterColumnsBlockInputStream>(stream, real_column_names, true);
/// Subordinary tables could have different but convertible types, like numeric types of different width.
/// We must return streams with structure equals to structure of Merge table.
for (auto & stream : source_streams)
@ -249,6 +255,10 @@ BlockInputStreams StorageMerge::read(
throw Exception("Source tables for Merge table are processing data up to different stages",
ErrorCodes::INCOMPATIBLE_SOURCE_TABLES);
if (processed_stage_in_source_table == QueryProcessingStage::FetchColumns)
for (auto & stream : streams)
stream = std::make_shared<FilterColumnsBlockInputStream>(stream, real_column_names, true);
auto stream = streams.empty() ? std::make_shared<NullBlockInputStream>(header) : streams.front();
if (!streams.empty())
{

3000
dbms/tests/queries/0_stateless/00579_virtual_column_and_lazy.reference Normal file
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File diff suppressed because it is too large Load Diff

18
dbms/tests/queries/0_stateless/00579_virtual_column_and_lazy.sql Normal file
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@ -0,0 +1,18 @@
DROP TABLE IF EXISTS test.sample1;
DROP TABLE IF EXISTS test.sample2;
DROP TABLE IF EXISTS test.sample_merge;
CREATE TABLE test.sample1 (x UInt64, d Date DEFAULT today()) ENGINE = MergeTree(d, intHash64(x), intHash64(x), 10);
CREATE TABLE test.sample2 (x UInt64, d Date DEFAULT today()) ENGINE = MergeTree(d, intHash64(x), intHash64(x), 10);
INSERT INTO test.sample1 (x) SELECT number AS x FROM system.numbers LIMIT 1000;
INSERT INTO test.sample2 (x) SELECT number AS x FROM system.numbers LIMIT 2000;
CREATE TABLE test.sample_merge AS test.sample1 ENGINE = Merge(test, '^sample\\d$');
SET max_threads = 1;
SELECT _sample_factor FROM merge(test, '^sample\\d$');
DROP TABLE test.sample1;
DROP TABLE test.sample2;
DROP TABLE test.sample_merge;