arangosh> var stmt = db._createStatement("FOR doc IN @@collection FILTER doc.user == @user RETURN doc");
arangosh> stmt.bind({ "@collection" : "_users", "user" : "root" });
arangosh> stmt.explain();
{ 
  "plan" : { 
    "nodes" : [ 
      { 
        "type" : "SingletonNode", 
        "dependencies" : [ ], 
        "id" : 1, 
        "estimatedCost" : 1, 
        "estimatedNrItems" : 1 
      }, 
      { 
        "type" : "IndexRangeNode", 
        "dependencies" : [ 
          1 
        ], 
        "id" : 6, 
        "estimatedCost" : 1.9899995050000001, 
        "estimatedNrItems" : 1, 
        "database" : "_system", 
        "collection" : "_users", 
        "outVariable" : { 
          "id" : 0, 
          "name" : "doc" 
        }, 
        "ranges" : [ 
          [ 
            { 
              "variable" : "doc", 
              "attr" : "user", 
              "lowConst" : { 
                "bound" : "root", 
                "include" : true, 
                "isConstant" : true 
              }, 
              "highConst" : { 
                "bound" : "root", 
                "include" : true, 
                "isConstant" : true 
              }, 
              "lows" : [ ], 
              "highs" : [ ], 
              "valid" : true, 
              "equality" : true 
            } 
          ] 
        ], 
        "index" : { 
          "type" : "hash", 
          "id" : "586635", 
          "unique" : true, 
          "sparse" : true, 
          "selectivityEstimate" : 1, 
          "fields" : [ 
            "user" 
          ] 
        }, 
        "reverse" : false 
      }, 
      { 
        "type" : "ReturnNode", 
        "dependencies" : [ 
          6 
        ], 
        "id" : 5, 
        "estimatedCost" : 2.989999505, 
        "estimatedNrItems" : 1, 
        "inVariable" : { 
          "id" : 0, 
          "name" : "doc" 
        } 
      } 
    ], 
    "rules" : [ 
      "use-index-range", 
      "remove-filter-covered-by-index" 
    ], 
    "collections" : [ 
      { 
        "name" : "_users", 
        "type" : "read" 
      } 
    ], 
    "variables" : [ 
      { 
        "id" : 2, 
        "name" : "1" 
      }, 
      { 
        "id" : 0, 
        "name" : "doc" 
      } 
    ], 
    "estimatedCost" : 2.989999505, 
    "estimatedNrItems" : 1 
  }, 
  "warnings" : [ ], 
  "stats" : { 
    "rulesExecuted" : 22, 
    "rulesSkipped" : 0, 
    "plansCreated" : 1 
  } 
}