slow create relationships

[Бушуев Роман]

Discussed in https://github.com/memgraph/gqlalchemy/discussions/224

^{Originally posted by POMXARK March 15, 2023}
Why is this code not working? if you run in the console everything works? is it possible to make multi requests?

from gqlalchemy import Memgraph

memgraph = Memgraph(host='127.0.0.1', port=7687)
memgraph.execute("""
MATCH (parent_stmt:TL), (child_stmt:TL)
WHERE parent_stmt.parent_stmt_id = 2 AND child_stmt.child_stmt_id = 4
CREATE (child_stmt)-[:STMT_BINDING {is_archived: 1}]->(parent_stmt);
MATCH (parent_stmt:TL), (child_stmt:TL)
WHERE parent_stmt.parent_stmt_id = 2 AND child_stmt.child_stmt_id = 6
CREATE (child_stmt)-[:STMT_BINDING {is_archived: 1}]->(parent_stmt); 
""")

optimization of this kind did not help

MATCH 
    (p_1:TL {parent_stmt_id: 2}), (child_stmt:TL {c_1: 4}), 
    (p_2:TL {parent_stmt_id: 3}), (child_stmt:TL {c_2: 6}),
CREATE 
     (p_1)-[:STMT_BINDING {is_archived: 1}]->(c_1),
    (p_2)-[:STMT_BINDING {is_archived: 0}]->(c_2)

average speed 40 requests/sec
to create 66 000 Relationships
time was spent 1:30 (hour and 30 minutes)
is there a way to optimize this?
if run in different threads it can help?

mgmigrate can perform 7000 requests per second, that is, this is a limitation of the python implementation?

[Ante Javor]

Hi @POMXARK, thanks for opening the issue. This is a very slow performance for these simple queries, which suggests something fundamentally wrong with the setup. Did you add indexes on labels and label + properties?
https://memgraph.com/docs/memgraph/reference-guide/indexing

[Бушуев Роман]

@antejavor Thank you for your response. No. Could you suggest what indexes need to be created?

[Ante Javor]

For the queries above, you need the following label+property index:

CREATE INDEX ON :TL(parent_stmt_id);
CREATE INDEX ON :TL(c_1);

If you will be doing MATCH on just label, not label + property, for example:

MATCH (node:TL)

You will also need a separate label index:

CREATE INDEX ON :TL;

But also take a look at the guide: https://memgraph.com/docs/memgraph/under-the-hood/indexing

[Josipmrden]

CREATE INDEX ON :TL(c_2); CREATE INDEX ON :TL(child_stmt_id);
as well

[Josipmrden]

@POMXARK at the moment gqlalchemy does not offer multiple commands inside one execute_and_fetch.

Mgconsole I think parses it and then executes every method by itself.

[Бушуев Роман]

@antejavor @Josipmrden thank you very much, the indicators have grown from 40 to 4000 requests per second. indexing is important)

CREATE INDEX ON :entity_0;
CREATE INDEX ON :entity_1;
CREATE INDEX ON :entity_0(user_id);
CREATE INDEX ON :entity_1(user_id);
SHOW INDEX INFO;

MATCH (parent:entity_0), (child:entity_1) 
WHERE parent.user_id = 0 AND child.user_id = 1  
CREATE (child)-[:tree_binging]->(parent)

[Бушуев Роман]

@antejavor @Josipmrden tell me is it possible to index relationships?

[Josipmrden]

At the moment that is not possible to index relationships