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Merge branch 'master' of github.com:ClickHouse/ClickHouse
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commit
ef9d80d996
@ -114,6 +114,7 @@
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M(SelectedRanges, "Number of (non-adjacent) ranges in all data parts selected to read from a MergeTree table.") \
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M(SelectedRanges, "Number of (non-adjacent) ranges in all data parts selected to read from a MergeTree table.") \
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M(SelectedMarks, "Number of marks (index granules) selected to read from a MergeTree table.") \
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M(SelectedMarks, "Number of marks (index granules) selected to read from a MergeTree table.") \
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\
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\
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M(Merge, "Number of launched background merges.") \
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M(MergedRows, "Rows read for background merges. This is the number of rows before merge.") \
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M(MergedRows, "Rows read for background merges. This is the number of rows before merge.") \
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M(MergedUncompressedBytes, "Uncompressed bytes (for columns as they stored in memory) that was read for background merges. This is the number before merge.") \
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M(MergedUncompressedBytes, "Uncompressed bytes (for columns as they stored in memory) that was read for background merges. This is the number before merge.") \
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M(MergesTimeMilliseconds, "Total time spent for background merges.")\
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M(MergesTimeMilliseconds, "Total time spent for background merges.")\
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@ -39,6 +39,7 @@ namespace ProfileEvents
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extern const Event MergedRows;
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extern const Event MergedRows;
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extern const Event MergedUncompressedBytes;
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extern const Event MergedUncompressedBytes;
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extern const Event MergesTimeMilliseconds;
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extern const Event MergesTimeMilliseconds;
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extern const Event Merge;
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}
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}
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namespace CurrentMetrics
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namespace CurrentMetrics
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@ -508,7 +509,10 @@ public:
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{
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{
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ProfileEvents::increment(ProfileEvents::MergedUncompressedBytes, value.read_bytes);
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ProfileEvents::increment(ProfileEvents::MergedUncompressedBytes, value.read_bytes);
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if (stage.is_first)
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if (stage.is_first)
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{
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ProfileEvents::increment(ProfileEvents::MergedRows, value.read_rows);
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ProfileEvents::increment(ProfileEvents::MergedRows, value.read_rows);
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ProfileEvents::increment(ProfileEvents::Merge);
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}
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updateWatch();
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updateWatch();
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merge_entry->bytes_read_uncompressed += value.read_bytes;
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merge_entry->bytes_read_uncompressed += value.read_bytes;
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@ -0,0 +1 @@
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1
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@ -0,0 +1,14 @@
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DROP TABLE IF EXISTS new_table_test;
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DROP TABLE IF EXISTS check_table_test;
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CREATE TABLE new_table_test(name String) ENGINE = MergeTree ORDER BY name;
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INSERT INTO new_table_test VALUES ('test');
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CREATE TABLE check_table_test(value1 UInt64, value2 UInt64) ENGINE = MergeTree ORDER BY tuple();
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INSERT INTO check_table_test (value1) SELECT value FROM system.events WHERE event = 'Merge';
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OPTIMIZE TABLE new_table_test FINAL;
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INSERT INTO check_table_test (value2) SELECT value FROM system.events WHERE event = 'Merge';
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SELECT count() FROM check_table_test WHERE value2 > value1;
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DROP TABLE new_table_test;
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DROP TABLE check_table_test;
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@ -251,6 +251,8 @@ Columns:
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- `value` ([Int64](../data_types/int_uint.md)) — Metric value.
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- `value` ([Int64](../data_types/int_uint.md)) — Metric value.
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- `description` ([String](../data_types/string.md)) — Metric description.
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- `description` ([String](../data_types/string.md)) — Metric description.
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The list of supported metrics you can find in the [dbms/src/Common/CurrentMetrics.cpp](https://github.com/ClickHouse/ClickHouse/blob/master/dbms/src/Common/CurrentMetrics.cpp) source file of ClickHouse.
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**Example**
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**Example**
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```sql
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```sql
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@ -10,7 +10,7 @@ Clickhouse 中最强大的表引擎当属 `MergeTree` (合并树)引擎及
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这让你可以创建一个用于快速检索数据的小稀疏索引。
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这让你可以创建一个用于快速检索数据的小稀疏索引。
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- 允许使用分区,如果指定了 [主键](custom_partitioning_key.md) 的话。
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- 允许使用分区,如果指定了 [分区键](custom_partitioning_key.md) 的话。
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在相同数据集和相同结果集的情况下 ClickHouse 中某些带分区的操作会比普通操作更快。查询中指定了分区键时 ClickHouse 会自动截取分区数据。这也有效增加了查询性能。
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在相同数据集和相同结果集的情况下 ClickHouse 中某些带分区的操作会比普通操作更快。查询中指定了分区键时 ClickHouse 会自动截取分区数据。这也有效增加了查询性能。
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