sqldb: improve serialization error handling

sqldb/interfaces.go

@@ -22,7 +22,7 @@ const (
 	// DefaultNumTxRetries is the default number of times we'll retry a
 	// transaction if it fails with an error that permits transaction
 	// repetition.
-	DefaultNumTxRetries = 10
+	DefaultNumTxRetries = 20
 
 	// DefaultRetryDelay is the default delay between retries. This will be
 	// used to generate a random delay between 0 and this value.