Dropping data, schema, and graphs

In Gremlin console, how to drop (delete) data, schema, and graphs.

Drop data

• To drop all data without dropping a graph and schema, drop all vertices.

  gremlin> g.V().drop().iterate()

• To drop specific data, such as all author vertices, identify the vertices along with a drop traversal step.

  gremlin> g.V().hasLabel('author').drop()

  Note: If a very large number of vertices will be dropped with the command shown above, DSE Graph may complain. In that case, modify the drop() command in the following manner:

  g.V().hasLabel('author').limit(100).drop()

  and repeat until all vertices are dropped.
• To drop a property key from an edge, such as rated edges, identify the edges, the property key stars along with a drop traversal step.

  gremlin> g.E().hasLabel('rated').properties('stars').drop()

  This query will drop the property key starsfor all edges that have a rated edge label.

  gremlin> g.E().hasLabel('rated').properties('stars').valueMap()

  returns no values.

  Warning: For data created earlier than DSE 5.0.5, conditions exist that will drop all edges as well as the edge property during a property key drop. See Dropping edge property drops edges.

Drop schema

• To drop the schema and all data without dropping the graph, use a clear() step. Running describe() after will verify that the schema is dropped. After the schema is dropped, new schema and data can be loaded to the graph.

  gremlin> schema.clear()

  ==>null

  Important: Currently, certain schema elements such as a vertex label cannot be individually modified or removed. If a change to the schema is necessary, drop the whole schema as detailed above and recreate.

Drop index

• To drop an index from the schema, such as the byMeal index, identify the index by name. Use describe() to examine all indexes for the desired vertex label.

  gremlin> schema.vertexLabel('meal').describe()

  ==>schema.vertexLabel('meal').properties("name").create()
  schema.vertexLabel('meal').index('byMeal').materialized().by('name').add()

• Using the vertex label and index name, remove the index. Running describe() again will verify that the index is removed.

  gremlin> schema.vertexLabel('meal').index('byMeal').remove()

  ==>null

Dropping a graph

• Dropping a graph will clear all schema and data as well as deleting the graph. A system command is required to drop a graph. In order to use system commands, the graph traversal alias must be cleared. A configuration reset clears the alias.

  gremlin> :remote config alias reset

  Note: System commands are not accessible when a graph is aliased.

  ==>Aliases cleared

• Optional: If unsure of the graph name, examine what graphs exist.

  gremlin> system.graphs()

  ==>food

• Drop the desired graph.

  gremlin> system.graph('food').drop()

  ==>null