diff --git a/client.go b/client.go
index f2c2f72..aca3350 100644
--- a/client.go
+++ b/client.go
@@ -362,7 +362,7 @@ func (c *Client) EnsureIndex(index *Index) error {
 	if err == ErrIndexExists {
 		return nil
 	}
-	return err
+	return errors.Wrap(err, "creating index")
 }
 
 // EnsureField creates a field on the server if it doesn't exists.
@@ -424,7 +424,7 @@ func (c *Client) syncSchema(schema *Schema, serverSchema *Schema) error {
 		if _, ok := serverSchema.indexes[indexName]; !ok {
 			err = c.EnsureIndex(index)
 			if err != nil {
-				return err
+				return errors.Wrap(err, "ensuring index")
 			}
 		}
 		for _, field := range index.fields {
diff --git a/gpexp/importbatch.go b/gpexp/importbatch.go
index 9ee21b6..4dd2fab 100644
--- a/gpexp/importbatch.go
+++ b/gpexp/importbatch.go
@@ -575,6 +575,9 @@ func (b *Batch) makeFragments() (fragments, error) {
 	}
 
 	for fname, rowIDSets := range b.rowIDSets {
+		if len(rowIDSets) == 0 {
+			continue
+		}
 		field := b.headerMap[fname]
 		opts := field.Opts()
 		curShard := ^uint64(0) // impossible sentinel value for shard.