Remove unused TableScan::ioWaitNanos_

Summary: This field is unused so clean it up.

Differential Revision: D56479031

velox/exec/TableScan.cpp

@@ -122,10 +122,6 @@ RowVectorPtr TableScan::getOutput() {
           const auto connectorStats = dataSource_->runtimeStats();
           auto lockedStats = stats_.wlock();
           for (const auto& [name, counter] : connectorStats) {
-            if (name == "ioWaitNanos") {
-              ioWaitNanos_ += counter.value - lastIoWaitNanos_;
-              lastIoWaitNanos_ = counter.value;
-            }
             if (FOLLY_UNLIKELY(lockedStats->runtimeStats.count(name) == 0)) {
               lockedStats->runtimeStats.emplace(
                   name, RuntimeMetric(counter.unit));

velox/exec/TableScan.h

@@ -49,13 +49,6 @@ class TableScan : public SourceOperator {
       column_index_t outputChannel,
       const std::shared_ptr<common::Filter>& filter) override;
 
-  /// Returns process-wide cumulative IO wait time for all table
-  /// scan. This is the blocked time. If running entirely from memory
-  /// this would be 0.
-  static uint64_t ioWaitNanos() {
-    return ioWaitNanos_;
-  }
-
  private:
   // Checks if this table scan operator needs to yield before processing the
   // next split.
@@ -76,9 +69,6 @@ class TableScan : public SourceOperator {
   // done, it will be made when needed.
   void preload(std::shared_ptr<connector::ConnectorSplit> split);
 
-  // Process-wide IO wait time.
-  inline static std::atomic<uint64_t> ioWaitNanos_;
-
   const std::shared_ptr<connector::ConnectorTableHandle> tableHandle_;
   const std::
       unordered_map<std::string, std::shared_ptr<connector::ColumnHandle>>
@@ -129,9 +119,5 @@ class TableScan : public SourceOperator {
   // Holds the current status of the operator. Used when debugging to understand
   // what operator is doing.
   std::atomic<const char*> curStatus_{""};
-
-  // The last value of the IO wait time of 'this' that has been added to the
-  // global static 'ioWaitNanos_'.
-  uint64_t lastIoWaitNanos_{0};
 };
 } // namespace facebook::velox::exec

velox/exec/tests/TableScanTest.cpp

@@ -270,7 +270,7 @@ TEST_F(TableScanTest, allColumns) {
   auto it = planStats.find(scanNodeId);
   ASSERT_TRUE(it != planStats.end());
   ASSERT_TRUE(it->second.peakMemoryBytes > 0);
-  EXPECT_LT(0, exec::TableScan::ioWaitNanos());
+  ASSERT_LT(0, it->second.customStats.at("ioWaitNanos").sum);
 }
 
 TEST_F(TableScanTest, connectorStats) {