Rename XStatistics to StatisticsX

Makes the naming more consistent with the rest of the codebase, e.g.
- MergeTreeIndexSet
- MergeTreeIndexMinMax

or
- StorageJoin
- StorageMergeTree

etc.

src/Storages/Statistics/Statistics.cpp

@@ -1,7 +1,7 @@
 #include <Storages/Statistics/Statistics.h>
 #include <Storages/Statistics/ConditionSelectivityEstimator.h>
-#include <Storages/Statistics/TDigestStatistics.h>
-#include <Storages/Statistics/UniqStatistics.h>
+#include <Storages/Statistics/StatisticsTDigest.h>
+#include <Storages/Statistics/StatisticsUniq.h>
 #include <Storages/StatisticsDescription.h>
 #include <Storages/ColumnsDescription.h>
 #include <IO/ReadHelpers.h>
@@ -44,7 +44,7 @@ void ColumnStatistics::update(const ColumnPtr & column)
 Float64 ColumnStatistics::estimateLess(Float64 val) const
 {
     if (stats.contains(StatisticsType::TDigest))
-        return std::static_pointer_cast<TDigestStatistics>(stats.at(StatisticsType::TDigest))->estimateLess(val);
+        return std::static_pointer_cast<StatisticsTDigest>(stats.at(StatisticsType::TDigest))->estimateLess(val);
     return rows * ConditionSelectivityEstimator::default_normal_cond_factor;
 }
 
@@ -57,12 +57,12 @@ Float64 ColumnStatistics::estimateEqual(Float64 val) const
 {
     if (stats.contains(StatisticsType::Uniq) && stats.contains(StatisticsType::TDigest))
     {
-        auto uniq_static = std::static_pointer_cast<UniqStatistics>(stats.at(StatisticsType::Uniq));
+        auto statistics_uniq = std::static_pointer_cast<StatisticsUniq>(stats.at(StatisticsType::Uniq));
         /// 2048 is the default number of buckets in TDigest. In this case, TDigest stores exactly one value (with many rows)
         /// for every bucket.
-        if (uniq_static->getCardinality() < 2048)
+        if (statistics_uniq->getCardinality() < 2048)
         {
-            auto tdigest_static = std::static_pointer_cast<TDigestStatistics>(stats.at(StatisticsType::TDigest));
+            auto tdigest_static = std::static_pointer_cast<StatisticsTDigest>(stats.at(StatisticsType::TDigest));
             return tdigest_static->estimateEqual(val);
         }
     }

src/Storages/Statistics/StatisticsTDigest.cpp

@@ -1,4 +1,4 @@
-#include <Storages/Statistics/TDigestStatistics.h>
+#include <Storages/Statistics/StatisticsTDigest.h>
 #include <DataTypes/DataTypeNullable.h>
 
 namespace DB
@@ -8,12 +8,12 @@ namespace ErrorCodes
     extern const int ILLEGAL_STATISTICS;
 }
 
-TDigestStatistics::TDigestStatistics(const SingleStatisticsDescription & stat_)
+StatisticsTDigest::StatisticsTDigest(const SingleStatisticsDescription & stat_)
     : IStatistics(stat_)
 {
 }
 
-void TDigestStatistics::update(const ColumnPtr & column)
+void StatisticsTDigest::update(const ColumnPtr & column)
 {
     size_t rows = column->size();
 
@@ -25,22 +25,22 @@ void TDigestStatistics::update(const ColumnPtr & column)
     }
 }
 
-void TDigestStatistics::serialize(WriteBuffer & buf)
+void StatisticsTDigest::serialize(WriteBuffer & buf)
 {
     t_digest.serialize(buf);
 }
 
-void TDigestStatistics::deserialize(ReadBuffer & buf)
+void StatisticsTDigest::deserialize(ReadBuffer & buf)
 {
     t_digest.deserialize(buf);
 }
 
-Float64 TDigestStatistics::estimateLess(Float64 val) const
+Float64 StatisticsTDigest::estimateLess(Float64 val) const
 {
     return t_digest.getCountLessThan(val);
 }
 
-Float64 TDigestStatistics::estimateEqual(Float64 val) const
+Float64 StatisticsTDigest::estimateEqual(Float64 val) const
 {
     return t_digest.getCountEqual(val);
 }
@@ -54,7 +54,7 @@ void TDigestValidator(const SingleStatisticsDescription &, DataTypePtr data_type
 
 StatisticsPtr TDigestCreator(const SingleStatisticsDescription & stat, DataTypePtr)
 {
-    return std::make_shared<TDigestStatistics>(stat);
+    return std::make_shared<StatisticsTDigest>(stat);
 }
 
 }

src/Storages/Statistics/StatisticsTDigest.h

@@ -6,10 +6,10 @@
 namespace DB
 {
 
-class TDigestStatistics : public IStatistics
+class StatisticsTDigest : public IStatistics
 {
 public:
-    explicit TDigestStatistics(const SingleStatisticsDescription & stat_);
+    explicit StatisticsTDigest(const SingleStatisticsDescription & stat_);
 
     void update(const ColumnPtr & column) override;
 

src/Storages/Statistics/StatisticsUniq.cpp

@@ -1,4 +1,4 @@
-#include <Storages/Statistics/UniqStatistics.h>
+#include <Storages/Statistics/StatisticsUniq.h>
 #include <DataTypes/DataTypesNumber.h>
 #include <DataTypes/DataTypeNullable.h>
 
@@ -10,7 +10,7 @@ namespace ErrorCodes
     extern const int ILLEGAL_STATISTICS;
 }
 
-UniqStatistics::UniqStatistics(const SingleStatisticsDescription & stat_, const DataTypePtr & data_type)
+StatisticsUniq::StatisticsUniq(const SingleStatisticsDescription & stat_, const DataTypePtr & data_type)
     : IStatistics(stat_)
 {
     arena = std::make_unique<Arena>();
@@ -20,12 +20,12 @@ UniqStatistics::UniqStatistics(const SingleStatisticsDescription & stat_, const
     collector->create(data);
 }
 
-UniqStatistics::~UniqStatistics()
+StatisticsUniq::~StatisticsUniq()
 {
     collector->destroy(data);
 }
 
-void UniqStatistics::update(const ColumnPtr & column)
+void StatisticsUniq::update(const ColumnPtr & column)
 {
     /// TODO(hanfei): For low cardinality, it's very slow to convert to full column. We can read the dictionary directly.
     /// Here we intend to avoid crash in CI.
@@ -34,17 +34,17 @@ void UniqStatistics::update(const ColumnPtr & column)
     collector->addBatchSinglePlace(0, column->size(), data, &(raw_ptr), nullptr);
 }
 
-void UniqStatistics::serialize(WriteBuffer & buf)
+void StatisticsUniq::serialize(WriteBuffer & buf)
 {
     collector->serialize(data, buf);
 }
 
-void UniqStatistics::deserialize(ReadBuffer & buf)
+void StatisticsUniq::deserialize(ReadBuffer & buf)
 {
     collector->deserialize(data, buf);
 }
 
-UInt64 UniqStatistics::getCardinality()
+UInt64 StatisticsUniq::getCardinality()
 {
     auto column = DataTypeUInt64().createColumn();
     collector->insertResultInto(data, *column, nullptr);
@@ -60,7 +60,7 @@ void UniqValidator(const SingleStatisticsDescription &, DataTypePtr data_type)
 
 StatisticsPtr UniqCreator(const SingleStatisticsDescription & stat, DataTypePtr data_type)
 {
-    return std::make_shared<UniqStatistics>(stat, data_type);
+    return std::make_shared<StatisticsUniq>(stat, data_type);
 }
 
 }

src/Storages/Statistics/StatisticsUniq.h

@@ -7,11 +7,11 @@
 namespace DB
 {
 
-class UniqStatistics : public IStatistics
+class StatisticsUniq : public IStatistics
 {
 public:
-    UniqStatistics(const SingleStatisticsDescription & stat_, const DataTypePtr & data_type);
-    ~UniqStatistics() override;
+    StatisticsUniq(const SingleStatisticsDescription & stat_, const DataTypePtr & data_type);
+    ~StatisticsUniq() override;
 
     void update(const ColumnPtr & column) override;
 

src/Storages/Statistics/tests/gtest_stats.cpp

@@ -1,6 +1,6 @@
 #include <gtest/gtest.h>
 
-#include <Storages/Statistics/TDigestStatistics.h>
+#include <Storages/Statistics/StatisticsTDigest.h>
 
 TEST(Statistics, TDigestLessThan)
 {