Very slow graph walk

[porscheme]

Version: v3.4.0
@wey-gu
Describe the bug (required)
Very slow graph walk...

• More than 5 minutes
• Often times crash
• Not able to run multiple queries this type in parallel

My Query

MATCH (p:Student)
WHERE id(p) IN [ ... ]

OPTIONAL MATCH (p)<-[:HAS_COURSE]-(a:CourseCodes)
OPTIONAL MATCH (p)<-[:STUDENT_HAS_SOCIAL]-(s:Social)
OPTIONAL MATCH (p)<-[:HAS_PROCEDURE]-(r:ProcedureCodes)

WITH
  p,
  COLLECT(DISTINCT a.CourseCodes.CodeId) as courses,
  COLLECT(DISTINCT s.Social.AttributeId) as social,
  COLLECT(DISTINCT r.ProcedureCodes.CodeId) as procedures

RETURN 
  p.Student.StudentId as Student, 
  p.Student.Gender as sex, 
  p.Student.Race as race, 
  p.Student.Ethnicity as ethnicity, 
  p.Student.MaritalStatus as maritalstatus,
  diagnosis,
  procedures,
  social

Your Environments (required)

• OS: uname -a
  Linux nebula-cluster-storaged-2 5.4.0-1103-azure Fixed all lint errors #109~18.04.1-Ubuntu SMP Wed Jan 25 20:53:00 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

• Compiler: g++ --version or clang++ --version
  g++: command not found

• CPU: lscpu

• Commit id (e.g. a3ffc7d8)

How To Reproduce(required)

Steps to reproduce the behavior:

1. Step 1
2. Step 2
3. Step 3

Expected behavior

Additional context

[wey-gu]

Could you share the profile of the query?

[wey-gu]

OPTIONAL MATCH (p)<-[:HAS_COURSE]-(a:CourseCodes)
OPTIONAL MATCH (p)<-[:STUDENT_HAS_SOCIAL]-(s:Social)
OPTIONAL MATCH (p)<-[:HAS_PROCEDURE]-(r:ProcedureCodes)

• Always put a tag when it's predictable/known, else, it had to scan for all tags on given p.
  like

OPTIONAL MATCH (p: Student)<-[:HAS_COURSE]-(a:CourseCodes)
OPTIONAL MATCH (p: Student)<-[:STUDENT_HAS_SOCIAL]-(s:Social)
OPTIONAL MATCH (p: Student)<-[:HAS_PROCEDURE]-(r:ProcedureCodes)

• explicitly provide props you cared under p in the first WITH, which will reduce the data being joined/aggregated.

Also, from the profile log you shared, it's not like 5 mins to me. I think the 5 mins was from studio?

[porscheme]

Also, from the profile log you shared, it's not like 5 mins to me. I think the 5 mins was from studio?
No, Its not from studio. Using python client library.

We use array of size about 200 in the below. its taking about 5 minutes.
'''
MATCH (p:Student)
WHERE id(p) IN [ ... ]
'''

[wey-gu]

let's talk in #5403, which seems to be the same topic.

As @yixinglu suggested, some conf changes may help.

Profile log queried from the nebula-console(in ASCII table not in CSV) could be shared there, too.

Thanks!