Hi all I m trying to display all the nodes and edges using t

Question

Hi all I m trying to display all the nodes and edges using the following query MATCH m e gt n RETURN m n e limit 10 But I m getting the following error Scan vertices or edges need to specify a limit number or limit number can not push down Can someone please clarify

wey · Answer

Dear Sandeep welcome to the NebulaGraph community slightly smiling face Will come back to you seen I am on a meeting now you could have a look at index related doc post first I will come back with more explanation later after the meeting

Sandeep · Answer

Hi < wey> Thanks for the quick reply and sharing the reference links I ll check them out To provide more context on my query I m using Nebula studio and I need all the available nodes and edges to be displayed as connected graph representation

wey · Answer

Hi < Sandeep> Sorry for the late follow up The Long version comes In NebulaGraph ` m e gt n RETURN m n e limit 10`was not allowed by complaining cannot be pushed down is due to we forbidden queries introducing full scan of data By full scan I am referring to this pattern didn t specify any vertex or edge types thus the limit cannot be pushed down to the storage side when scanning data More specifically in graphD it will construct an execution plan to starting from scan of vertex or edge or index is there is any then get neighbors etc the case without any tag edge type cannot be efficiently pushdown as nebulaGraph was designed schemaFul to enable high perf for large scale data Thus the mind module in NebulaGraph with Cypher to sample node edges could be When no indexes were created on tag or edge ```match e follow| serve gt return e limit 100``` or ```match v player return v limit 10``` Where we put all edge types and tags where it could scan edges with limit sample pushdown Or if we have created indexes on any tag or edge queries like gt when there is index on tag player ```match v player e follow| serve gt v1 return v e v1```

wey · Answer

gt To provide more context on my query I m using Nebula studio and I need all the available nodes and edges to be displayed as connected graph representation Let s take an example of basketballplayer dataset ref ref ```CREATE TAG INDEX IF NOT EXISTS player index 1 on player name 10 age REBUILD TAG INDEX player index 1 SHOW TAG INDEX STATUS ``` After indexes were rebuilt then this query will give us all player nodes and its outgoing connected nodes ```match v player e follow| serve gt v1 return v e v1```

Sandeep · Answer

Hi < wey> Sorry for the late response Thanks a lot for the detailed explanation