diff --git a/processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperUniqueFinalizingPostAggregator.java b/processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperUniqueFinalizingPostAggregator.java
index dd212df3f8d..e84bb5ab5fc 100644
--- a/processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperUniqueFinalizingPostAggregator.java
+++ b/processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperUniqueFinalizingPostAggregator.java
@@ -89,4 +89,39 @@ public class HyperUniqueFinalizingPostAggregator implements PostAggregator
   {
     return fieldName;
   }
+
+  @Override
+  public boolean equals(Object o)
+  {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
+    }
+
+    HyperUniqueFinalizingPostAggregator that = (HyperUniqueFinalizingPostAggregator) o;
+
+    if (name != null ? !name.equals(that.name) : that.name != null) {
+      return false;
+    }
+    return fieldName != null ? fieldName.equals(that.fieldName) : that.fieldName == null;
+  }
+
+  @Override
+  public int hashCode()
+  {
+    int result = name != null ? name.hashCode() : 0;
+    result = 31 * result + (fieldName != null ? fieldName.hashCode() : 0);
+    return result;
+  }
+
+  @Override
+  public String toString()
+  {
+    return "HyperUniqueFinalizingPostAggregator{" +
+           "name='" + name + '\'' +
+           ", fieldName='" + fieldName + '\'' +
+           '}';
+  }
 }
diff --git a/processing/src/main/java/io/druid/query/extraction/TimeFormatExtractionFn.java b/processing/src/main/java/io/druid/query/extraction/TimeFormatExtractionFn.java
index 31ae02ac918..4925246fc64 100644
--- a/processing/src/main/java/io/druid/query/extraction/TimeFormatExtractionFn.java
+++ b/processing/src/main/java/io/druid/query/extraction/TimeFormatExtractionFn.java
@@ -34,8 +34,8 @@ import java.util.Locale;
 
 public class TimeFormatExtractionFn implements ExtractionFn
 {
-  private final DateTimeZone tz;
   private final String format;
+  private final DateTimeZone tz;
   private final Locale locale;
   private final QueryGranularity granularity;
   private final DateTimeFormatter formatter;
@@ -161,4 +161,10 @@ public class TimeFormatExtractionFn implements ExtractionFn
     result = 31 * result + granularity.hashCode();
     return result;
   }
+
+  @Override
+  public String toString()
+  {
+    return String.format("timeFormat(\"%s\", %s, %s, %s)", format, tz, locale, granularity);
+  }
 }
diff --git a/processing/src/main/java/io/druid/query/filter/InDimFilter.java b/processing/src/main/java/io/druid/query/filter/InDimFilter.java
index cdf649366a5..8d6b25053f5 100644
--- a/processing/src/main/java/io/druid/query/filter/InDimFilter.java
+++ b/processing/src/main/java/io/druid/query/filter/InDimFilter.java
@@ -22,6 +22,7 @@ package io.druid.query.filter;
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.base.Function;
+import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
 import com.google.common.base.Strings;
 import com.google.common.base.Supplier;
@@ -40,6 +41,7 @@ import io.druid.segment.filter.InFilter;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Objects;
@@ -59,7 +61,7 @@ public class InDimFilter implements DimFilter
   @JsonCreator
   public InDimFilter(
       @JsonProperty("dimension") String dimension,
-      @JsonProperty("values") List<String> values,
+      @JsonProperty("values") Collection<String> values,
       @JsonProperty("extractionFn") ExtractionFn extractionFn
   )
   {
@@ -227,6 +229,26 @@ public class InDimFilter implements DimFilter
     return result;
   }
 
+  @Override
+  public String toString()
+  {
+    final StringBuilder builder = new StringBuilder();
+
+    if (extractionFn != null) {
+      builder.append(extractionFn).append("(");
+    }
+
+    builder.append(dimension);
+
+    if (extractionFn != null) {
+      builder.append(")");
+    }
+
+    builder.append(" IN (").append(Joiner.on(", ").join(values)).append(")");
+
+    return builder.toString();
+  }
+
   // As the set of filtered values can be large, parsing them as longs should be done only if needed, and only once.
   // Pass in a common long predicate supplier to all filters created by .toFilter(), so that
   // we only compute the long hashset/array once per query.
diff --git a/processing/src/main/java/io/druid/query/topn/DimensionTopNMetricSpec.java b/processing/src/main/java/io/druid/query/topn/DimensionTopNMetricSpec.java
index 686d1add701..6ffae4ab945 100644
--- a/processing/src/main/java/io/druid/query/topn/DimensionTopNMetricSpec.java
+++ b/processing/src/main/java/io/druid/query/topn/DimensionTopNMetricSpec.java
@@ -146,7 +146,7 @@ public class DimensionTopNMetricSpec implements TopNMetricSpec
   {
     return "DimensionTopNMetricSpec{" +
            "previousStop='" + previousStop + '\'' +
-           "ordering='" + ordering + '\'' +
+           ", ordering=" + ordering +
            '}';
   }
 
diff --git a/processing/src/main/java/io/druid/query/topn/InvertedTopNMetricSpec.java b/processing/src/main/java/io/druid/query/topn/InvertedTopNMetricSpec.java
index ceee9ae8c36..9332b60ef09 100644
--- a/processing/src/main/java/io/druid/query/topn/InvertedTopNMetricSpec.java
+++ b/processing/src/main/java/io/druid/query/topn/InvertedTopNMetricSpec.java
@@ -165,4 +165,12 @@ public class InvertedTopNMetricSpec implements TopNMetricSpec
   {
     return delegate != null ? delegate.hashCode() : 0;
   }
+
+  @Override
+  public String toString()
+  {
+    return "InvertedTopNMetricSpec{" +
+           "delegate=" + delegate +
+           '}';
+  }
 }