# Gremlin step coverage in DFE
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 Gremlin DFE is a labmode feature and can be used by either enabling the cluster parameter or using the `Neptune#useDFE` query hint. For more information please refer to [ Using Gremlin with the Neptune DFE query engine](https://docs.aws.amazon.com//neptune/latest/userguide/gremlin-with-dfe.html). 

 The following steps are available to use in Gremlin DFE. 

## Path and traversal steps:
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 [asDate()](https://tinkerpop.apache.org/docs/current/reference/#asDate-step), [barrier()](https://tinkerpop.apache.org/docs/current/reference/#barrier-step), [call()](https://tinkerpop.apache.org/docs/current/reference/#call-step), [cap()](https://tinkerpop.apache.org/docs/current/reference/#cap-step), [dateAdd()](https://tinkerpop.apache.org/docs/current/reference/#dateadd-step), [dateDiff()](https://tinkerpop.apache.org/docs/current/reference/#datediff-step), [disjunct()](https://tinkerpop.apache.org/docs/current/reference/#disjunct-step), [drop()](https://tinkerpop.apache.org/docs/current/reference/#drop-step), [fail()](https://tinkerpop.apache.org/docs/current/reference/#fail-step), [filter()](https://tinkerpop.apache.org/docs/current/reference/#filter-step), [flatMap()](https://tinkerpop.apache.org/docs/current/reference/#flatmap-step), [id()](https://tinkerpop.apache.org/docs/current/reference/#id-step), [identity()](https://tinkerpop.apache.org/docs/current/reference/#identity-step), [index()](https://tinkerpop.apache.org/docs/current/reference/#index-step), [intersect()](https://tinkerpop.apache.org/docs/current/reference/#intersect-step), [inject()](https://tinkerpop.apache.org/docs/current/reference/#inject-step), [label()](https://tinkerpop.apache.org/docs/current/reference/#label-step), [length()](https://tinkerpop.apache.org/docs/current/reference/#length-step), [loops()](https://tinkerpop.apache.org/docs/current/reference/#loops-step), [map()](https://tinkerpop.apache.org/docs/current/reference/#map-step), [order()](https://tinkerpop.apache.org/docs/current/reference/#order-step), [order(local)](https://tinkerpop.apache.org/docs/current/reference/#order-step), [path()](https://tinkerpop.apache.org/docs/current/reference/#path-step), [project()](https://tinkerpop.apache.org/docs/current/reference/#project-step), [range()](https://tinkerpop.apache.org/docs/current/reference/#range-step), [repeat()](https://tinkerpop.apache.org/docs/current/reference/#repeat-step), [reverse()](https://tinkerpop.apache.org/docs/current/reference/#reverse-step), [sack()](https://tinkerpop.apache.org/docs/current/reference/#sack-step), [sample()](https://tinkerpop.apache.org/docs/current/reference/#sample-step), [select()](https://tinkerpop.apache.org/docs/current/reference/#select-step), [sideEffect()](https://tinkerpop.apache.org/docs/current/reference/#sideeffect-step), [split()](https://tinkerpop.apache.org/docs/current/reference/#split-step), [unfold()](https://tinkerpop.apache.org/docs/current/reference/#unfold-step), [union()](https://tinkerpop.apache.org/docs/current/reference/#union-step) 

## Aggregate and collection steps:
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 [aggregate(global)](https://tinkerpop.apache.org/docs/current/reference/#aggregate-step), [combine()](https://tinkerpop.apache.org/docs/current/reference/#combine-step), [count()](https://tinkerpop.apache.org/docs/current/reference/#count-step), [dedup()](https://tinkerpop.apache.org/docs/current/reference/#dedup-step), [dedup(local)](https://tinkerpop.apache.org/docs/current/reference/#dedup-step), [fold()](https://tinkerpop.apache.org/docs/current/reference/#fold-step), [group()](https://tinkerpop.apache.org/docs/current/reference/#group-step), [groupCount()](https://tinkerpop.apache.org/docs/current/reference/#groupcount-step), 

## Mathematical steps:
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 [max()](https://tinkerpop.apache.org/docs/current/reference/#max-step), [mean()](https://tinkerpop.apache.org/docs/current/reference/#mean-step), [min()](https://tinkerpop.apache.org/docs/current/reference/#min-step), [sum()](https://tinkerpop.apache.org/docs/current/reference/#sum-step) 

## Element steps:
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 [otherV()](https://tinkerpop.apache.org/docs/current/reference/#otherv-step), [elementMap()](https://tinkerpop.apache.org/docs/current/reference/#elementmap-step), [element()](https://tinkerpop.apache.org/docs/current/reference/#element-step), [v()](https://tinkerpop.apache.org/docs/current/reference/#graph-step), [ out(), in(), both(), outE(), inE(), bothE(), outV(), inV(), bothV(), otherV()](https://tinkerpop.apache.org/docs/current/reference/#vertex-step) 

## Property steps:
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 [properties()](https://tinkerpop.apache.org/docs/current/reference/#properties-step), [key()](https://tinkerpop.apache.org/docs/current/reference/#key-step), [valueMap()](https://tinkerpop.apache.org/docs/current/reference/#propertymap-step), [value()](https://tinkerpop.apache.org/docs/current/reference/#value-step) 

## Filter steps:
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 [and()](https://tinkerpop.apache.org/docs/current/reference/#and-step), [coalesce()](https://tinkerpop.apache.org/docs/current/reference/#coalesce-step), [coin()](https://tinkerpop.apache.org/docs/current/reference/#coin-step), [has()](https://tinkerpop.apache.org/docs/current/reference/#has-step), [is()](https://tinkerpop.apache.org/docs/current/reference/#is-step), [local()](https://tinkerpop.apache.org/docs/current/reference/#local-step), [none()](https://tinkerpop.apache.org/docs/current/reference/#none-step), [not()](https://tinkerpop.apache.org/docs/current/reference/#not-step), [or()](https://tinkerpop.apache.org/docs/current/reference/#or-step), [where()](https://tinkerpop.apache.org/docs/current/reference/#where-step) 

## String manipulation steps:
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 [concat()](https://tinkerpop.apache.org/docs/current/reference/#concat-step), [lTrim()](https://tinkerpop.apache.org/docs/current/reference/#lTrim-step), [rTrim()](https://tinkerpop.apache.org/docs/current/reference/#rtrim-step), [substring()](https://tinkerpop.apache.org/docs/current/reference/#substring-step), [toLower()](https://tinkerpop.apache.org/docs/current/reference/#toLower-step), [toUpper()](https://tinkerpop.apache.org/docs/current/reference/#toUpper-step), [trim()](https://tinkerpop.apache.org/docs/current/reference/#trim-step) 

## Predicates:
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+  [ Compare: eq, neq, lt, lte, gt, gte](https://tinkerpop.apache.org/docs/current/reference/#a-note-on-predicates) 
+  [Contains: within, without](https://tinkerpop.apache.org/docs/current/reference/#a-note-on-predicates) 
+  [ TextP: endingWith, containing, notStartingWith, notEndingWith, notContaining](https://tinkerpop.apache.org/docs/current/reference/#a-note-on-predicates) 
+  [ P: and, or, between, outside, inside](https://tinkerpop.apache.org/docs/current/reference/#a-note-on-predicates) 

## Limitations
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 Repeat with Limit, Labels inside repeat traversal and dedup are not supported in DFE yet. 

```
// With Limit inside the repeat traversal
  g.V().has('code','AGR').repeat(out().limit(5)).until(has('code','FRA'))
  
  // With Labels inside the repeat traversal
  g.V().has('code','AGR').repeat(out().as('a')).until(has('code','FRA'))
  
  // With Dedup inside the repeat traversal
  g.V().has('code','AGR').repeat(out().dedup()).until(has('code','FRA'))
```

 Path with nested repeats, or branching steps are not supported yet. 

```
// Path with branching steps
  g.V().has('code','AGR').union(identity, outE().inV()).path().by('code')
  
  
  // With nested repeat
  g.V().has('code','AGR').repeat(out().union(identity(), out())).path().by('code')
```