# General Best Practices for Using Gremlin with Neptune
<a name="best-practices-gremlin"></a>

Follow these recommendations when using the Gremlin graph traversal language with Neptune. For information about using Gremlin with Neptune, see [Accessing a Neptune graph with Gremlin](access-graph-gremlin.md).

**Important**  
A change was made in TinkerPop version 3.4.11 that improves correctness of how queries are processed, but for the moment can sometimes seriously impact query performance.  
For example, a query of this sort may run significantly slower:  

```
g.V().hasLabel('airport').
  order().
    by(out().count(),desc).
  limit(10).
  out()
```
The vertices after the limit step are now fetched in a non-optimal way because of the TinkerPop 3.4.11 change. To avoid this, you can modify the query by adding the barrier() step at any point after the `order().by()`. For example:  

```
g.V().hasLabel('airport').
  order().
    by(out().count(),desc).
  limit(10).
  barrier().
  out()
```
TinkerPop 3.4.11 was enabled in Neptune [engine version 1.0.5.0](engine-releases-1.0.5.0.md).

**Topics**
+ [Heartbeat Configuration for Neptune Serverless](best-practices-gremlin-heartbeat-serverless.md)
+ [Structure upsert queries to take advantage of the DFE engine](#best-practices-gremlin-upserts)
+ [Test Gremlin code in the context where you will deploy it](best-practices-gremlin-console-glv-differences.md)
+ [Creating Efficient Multithreaded Gremlin Writes](best-practices-gremlin-multithreaded-writes.md)
+ [Pruning Records with the Creation Time Property](best-practices-gremlin-prune.md)
+ [Using the `datetime( )` Method for Groovy Time Data](best-practices-gremlin-datetime.md)
+ [Using Native Date and Time for GLV Time Data](best-practices-gremlin-datetime-glv.md)

## Structure upsert queries to take advantage of the DFE engine
<a name="best-practices-gremlin-upserts"></a>

[Making efficient upserts with Gremlin `mergeV()` and `mergeE()` steps](gremlin-efficient-upserts.md) explains how to structure upsert queries to use the DFE engine as effectively as possible.