core/src/main/java/com/orientechnologies/orient/core/storage/impl/local/statistic/OSessionStoragePerformanceStatistic.java
public void startComponentOperation(String componentName, ComponentType type) {
    final Component currentComponent = componentsStack.peek();

    if (currentComponent != null && componentName.equals(currentComponent.name)) {
      currentComponent.operationCount++;
      return;
    }

    componentsStack.push(new Component(componentName, type));
  }
public void startComponentOperation(String componentName, ComponentType type) {
    final Component currentComponent = componentsStack.peek();

    if (currentComponent != null && componentName.equals(currentComponent.name)) {
      currentComponent.operationCount++;
      return;
    }

    componentsStack.push(new Component(componentName, type));
  }
Called inside of {@link com.orientechnologies.orient.core.storage.impl.local.paginated.base.ODurableComponent} to notify that
component started to perform operation on data. After that all performance characteristic started to be gathered for this
component till method {@link #completeComponentOperation()} will be called.
<p>
Components can be stacked, so if components <code>c1</code> and then <code>c2</code> call this method than performance data for
both components at once started to be gathered.

@param componentName Name of component which started to perform operation on data. Name is case sensitive.