Yes, it implies an index. And yes, you do need to drop it to add a unique constraint.
Wes On Sun, Dec 22, 2013 at 10:17 PM, Javad Karabi <[email protected]>wrote: > looks like i need to drop the index first? > > just to be clear, if a constraint is added, does this imply an index? > so, i dont need to worry about adding an index after i add a constraint? > > > On Sunday, December 22, 2013 8:39:49 PM UTC-6, Javad Karabi wrote: >> >> Michael, i already have the id field indexed, does this not guarantee >> uniqueness? >> >> I ask because the result of >> CREATE CONSTRAINT ON (m:Member) ASSERT m.id IS UNIQUE >> is >> Already indexed :Member(id). >> >> >> On Sunday, December 22, 2013 7:45:37 PM UTC-6, Michael Hunger wrote: >>> >>> try to create a unique constraint on a label and your "id" field. >>> >>> That will take an lock then to assure unique creation. >>> >>> Michael >>> >>> Am 23.12.2013 um 02:00 schrieb Javad Karabi <[email protected]>: >>> >>> if i have 2 cypher query posts to neo4j >>> >>> "MERGE a:Member( {id: {member_id} })" , member_id: 5 >>> >>> "MERGE a:Member( {id: {member_id} })" , member_id: 5 >>> >>> with both of these posts occurring simultaneously, is it possible to >>> have 2 nodes created, instead of just the one? >>> that is, if the first merge was interrupted halfway though, and had not >>> completed yet, the second then creates a new one since it doesnt see the >>> first... >>> is this something that could potentially happen? >>> >>> on a related note, how would i enforce uniqueness on Member(id) ? >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Neo4j" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> For more options, visit https://groups.google.com/groups/opt_out. >>> >>> >>> -- > You received this message because you are subscribed to the Google Groups > "Neo4j" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- You received this message because you are subscribed to the Google Groups "Neo4j" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
