diff --git a/dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/ConnectorArguments.java b/dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/ConnectorArguments.java
index a240284a9..6881b9000 100644
--- a/dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/ConnectorArguments.java
+++ b/dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/ConnectorArguments.java
@@ -943,6 +943,10 @@ public String getQueryLogEarliestTimestamp() {
     return getOptions().valueOf(optionQueryLogEarliestTimestamp);
   }
 
+  public boolean hasQueryLogEarliestTimestamp() {
+    return getOptions().valueOf(optionQueryLogEarliestTimestamp) != null;
+  }
+
   @CheckForNull
   public Integer getQueryLogDays() {
     return getOptions().valueOf(optionQueryLogDays);
diff --git a/dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/connector/snowflake/SnowflakeLogsConnector.java b/dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/connector/snowflake/SnowflakeLogsConnector.java
index d6d4c8354..c2ae20a0f 100644
--- a/dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/connector/snowflake/SnowflakeLogsConnector.java
+++ b/dumper/app/src/main/java/com/google/edwmigration/dumper/application/dumper/connector/snowflake/SnowflakeLogsConnector.java
@@ -160,6 +160,15 @@ private TaskDescription(
     }
   }
 
+  @Override
+  public final void validate(ConnectorArguments arguments) {
+    super.validate(arguments);
+
+    if (arguments.isAssessment() && arguments.hasQueryLogEarliestTimestamp()) {
+      throw unsupportedOption(ConnectorArguments.OPT_QUERY_LOG_EARLIEST_TIMESTAMP);
+    }
+  }
+
   @Nonnull
   @Override
   public Class<? extends Enum<? extends ConnectorProperty>> getConnectorProperties() {
@@ -281,8 +290,6 @@ private String createExtendedQueryFromAccountUsage(ConnectorArguments arguments)
     String overrideQuery = getOverrideQuery(arguments);
     if (overrideQuery != null) return overrideQuery;
 
-    String overrideWhere = getOverrideWhere(arguments);
-
     @SuppressWarnings("OrphanedFormatString")
     StringBuilder queryBuilder =
         new StringBuilder(
@@ -333,12 +340,8 @@ private String createExtendedQueryFromAccountUsage(ConnectorArguments arguments)
                 + "WHERE end_time >= to_timestamp_ltz('%s')\n"
                 + "AND end_time <= to_timestamp_ltz('%s')\n"
                 + "AND is_client_generated_statement = FALSE\n");
-    if (!StringUtils.isBlank(arguments.getQueryLogEarliestTimestamp()))
-      queryBuilder
-          .append("AND start_time >= ")
-          .append(arguments.getQueryLogEarliestTimestamp())
-          .append("\n");
-    if (overrideWhere != null) queryBuilder.append(" AND ").append(overrideWhere);
+
+    queryBuilder.append(getOverrideWhere(arguments));
     return queryBuilder.toString().replace('\n', ' ');
   }
 
@@ -356,16 +359,25 @@ private String getOverrideQuery(@Nonnull ConnectorArguments arguments)
     return null;
   }
 
-  @CheckForNull
+  @Nonnull
   private String getOverrideWhere(@Nonnull ConnectorArguments arguments)
       throws MetadataDumperUsageException {
-    return arguments.getDefinition(SnowflakeLogConnectorProperties.OVERRIDE_WHERE);
+    ConnectorProperty property = SnowflakeLogConnectorProperties.OVERRIDE_WHERE;
+    String overrideWhere = arguments.getDefinition(property);
+    if (overrideWhere != null) {
+      return String.format(" AND %s", overrideWhere);
+    } else {
+      return "";
+    }
   }
 
   @Override
   public final void addTasksTo(
       @Nonnull List<? super Task<?>> out, @Nonnull ConnectorArguments arguments)
       throws MetadataDumperUsageException {
+
+    boolean isAssessment = arguments.isAssessment();
+
     out.add(new DumpMetadataTask(arguments, FORMAT_NAME));
     out.add(new FormatTask(FORMAT_NAME));
 
@@ -380,7 +392,7 @@ public final void addTasksTo(
             arguments, rotationDuration, IntervalExpander.createBasedOnDuration(rotationDuration));
     logger.info("Exporting query log for " + queryLogIntervals);
 
-    if (!arguments.isAssessment()) {
+    if (!isAssessment) {
       TaskDescription queryHistoryTask =
           new TaskDescription(ZIP_ENTRY_PREFIX, newQueryFormat(arguments), Header.class);
       queryLogIntervals.forEach(interval -> addJdbcTask(out, interval, queryHistoryTask));
@@ -413,6 +425,13 @@ private static void addJdbcTask(
     out.add(new JdbcSelectTask(file, query, task.taskCategory).withHeaderClass(task.headerClass));
   }
 
+  private static MetadataDumperUsageException unsupportedOption(String option) {
+    String assessment = ConnectorArguments.OPT_ASSESSMENT;
+    String message =
+        String.format("Unsupported option used with --%s: please remove --%s", assessment, option);
+    return new MetadataDumperUsageException(message);
+  }
+
   private String getOverrideableQuery(
       @Nullable String overrideQuery, @Nonnull String defaultSql, @Nonnull String whereField) {
     String sql = overrideQuery != null ? overrideQuery : defaultSql;
diff --git a/dumper/app/src/test/java/com/google/edwmigration/dumper/application/dumper/connector/snowflake/SnowflakeLogsConnectorTest.java b/dumper/app/src/test/java/com/google/edwmigration/dumper/application/dumper/connector/snowflake/SnowflakeLogsConnectorTest.java
index 4edf35f23..5d4f720dd 100644
--- a/dumper/app/src/test/java/com/google/edwmigration/dumper/application/dumper/connector/snowflake/SnowflakeLogsConnectorTest.java
+++ b/dumper/app/src/test/java/com/google/edwmigration/dumper/application/dumper/connector/snowflake/SnowflakeLogsConnectorTest.java
@@ -17,9 +17,13 @@
 package com.google.edwmigration.dumper.application.dumper.connector.snowflake;
 
 import com.google.common.base.Predicates;
+import com.google.edwmigration.dumper.application.dumper.ConnectorArguments;
+import com.google.edwmigration.dumper.application.dumper.MetadataDumperUsageException;
 import com.google.edwmigration.dumper.plugin.lib.dumper.spi.SnowflakeLogsDumpFormat;
 import com.google.edwmigration.dumper.test.TestUtils;
 import java.io.File;
+import java.io.IOException;
+import org.junit.Assert;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
@@ -41,4 +45,17 @@ public void testExecution() throws Exception {
 
     validator.run(outputFile);
   }
+
+  @Test
+  public void validate_unsupportedOption_throwsException() throws IOException {
+    ConnectorArguments arguments =
+        new ConnectorArguments(
+            "--connector",
+            "snowflake-logs",
+            "--assessment",
+            "--" + ConnectorArguments.OPT_QUERY_LOG_EARLIEST_TIMESTAMP,
+            "2024");
+
+    Assert.assertThrows(MetadataDumperUsageException.class, () -> connector.validate(arguments));
+  }
 }