Merge branch 'master' of github.com:ClickHouse/ClickHouse

dbms/src/Common/ProfileEvents.cpp

@@ -114,6 +114,7 @@
     M(SelectedRanges, "Number of (non-adjacent) ranges in all data parts selected to read from a MergeTree table.") \
     M(SelectedMarks, "Number of marks (index granules) selected to read from a MergeTree table.") \
     \
+    M(Merge, "Number of launched background merges.") \
     M(MergedRows, "Rows read for background merges. This is the number of rows before merge.") \
     M(MergedUncompressedBytes, "Uncompressed bytes (for columns as they stored in memory) that was read for background merges. This is the number before merge.") \
     M(MergesTimeMilliseconds, "Total time spent for background merges.")\

dbms/src/Storages/MergeTree/MergeTreeDataMergerMutator.cpp

@@ -39,6 +39,7 @@ namespace ProfileEvents
     extern const Event MergedRows;
     extern const Event MergedUncompressedBytes;
     extern const Event MergesTimeMilliseconds;
+    extern const Event Merge;
 }
 
 namespace CurrentMetrics
@@ -508,7 +509,10 @@ public:
     {
         ProfileEvents::increment(ProfileEvents::MergedUncompressedBytes, value.read_bytes);
         if (stage.is_first)
+        {
             ProfileEvents::increment(ProfileEvents::MergedRows, value.read_rows);
+            ProfileEvents::increment(ProfileEvents::Merge);
+        }
         updateWatch();
 
         merge_entry->bytes_read_uncompressed += value.read_bytes;

dbms/tests/queries/0_stateless/01014_count_of_merges_metrics.reference

@@ -0,0 +1 @@
+1

dbms/tests/queries/0_stateless/01014_count_of_merges_metrics.sql

@@ -0,0 +1,14 @@
+DROP TABLE IF EXISTS new_table_test;
+DROP TABLE IF EXISTS check_table_test;
+
+CREATE TABLE new_table_test(name String) ENGINE = MergeTree ORDER BY name;
+INSERT INTO new_table_test VALUES ('test');
+CREATE TABLE check_table_test(value1 UInt64, value2 UInt64) ENGINE = MergeTree ORDER BY tuple();
+INSERT INTO check_table_test (value1) SELECT value FROM system.events WHERE event = 'Merge';
+OPTIMIZE TABLE new_table_test FINAL;
+INSERT INTO check_table_test (value2) SELECT value FROM system.events WHERE event = 'Merge';
+SELECT count() FROM check_table_test WHERE value2 > value1;
+
+
+DROP TABLE new_table_test;
+DROP TABLE check_table_test;

docs/en/operations/system_tables.md

@@ -251,6 +251,8 @@ Columns:
 - `value` ([Int64](../data_types/int_uint.md)) — Metric value.
 - `description` ([String](../data_types/string.md)) — Metric description.
 
+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.
+
 **Example**
 
 ```sql

docs/zh/operations/table_engines/mergetree.md

@@ -10,7 +10,7 @@ Clickhouse 中最强大的表引擎当属 `MergeTree` （合并树）引擎及
 
     这让你可以创建一个用于快速检索数据的小稀疏索引。
 
-- 允许使用分区，如果指定了 [主键](custom_partitioning_key.md) 的话。
+- 允许使用分区，如果指定了 [分区键](custom_partitioning_key.md) 的话。
 
     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。