Wrong error msg of matching on vertex properties #3492

randomJoe211 · 2021-12-17T06:16:56Z

Please check the FAQ documentation before raising an issue

Been there.

Describe the bug (required)

When executing MATCH (v{name: "Tim Duncan"}) return v, it shows [ERROR (-1005)]: Scan vertices must specify limit number.

If I add LIMIT, it still tells me the same thing.

The error message is wrong. If matching on vertex properties is not supported, then the error message should tell me this, not a wrong reason.

Plus I have the following tag indexes:

Your Environments (required)

OS: Ubuntu 20.04
Commit id: nebula-graphd version 2021.12.15-nightly, Git: 99f1f7a, Build Time: Dec 16 2021 03:10:58

The text was updated successfully, but these errors were encountered:

Shylock-Hg · 2021-12-20T03:35:39Z

It's expected.
See the execution plan:

Execution Plan (optimize time 2731 us)

-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
| id | name           | dependencies | profiling data | operator info                                                                                |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
|  7 | DataCollect    | 11           |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__DataCollect_7"                                                                |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: [                                                                                  |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__Limit_6"                                                                      |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | kind: ROW                                                                                    |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
| 11 | Project        | 10           |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__Limit_6"                                                                      |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: __Project_5                                                                        |
|    |                |              |                | columns: [                                                                                   |
|    |                |              |                |   "$-.v AS v"                                                                                |
|    |                |              |                | ]                                                                                            |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
| 10 | Limit          | 3            |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "_vid",                                                                                |
|    |                |              |                |       "bachelor._tag",                                                                       |
|    |                |              |                |       "team._tag",                                                                           |
|    |                |              |                |       "player._tag",                                                                         |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__Project_5"                                                                    |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: __AppendVertices_3                                                                 |
|    |                |              |                | offset: 0                                                                                    |
|    |                |              |                | count: 3                                                                                     |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
|  3 | AppendVertices | 9            |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "_vid",                                                                                |
|    |                |              |                |       "bachelor._tag",                                                                       |
|    |                |              |                |       "team._tag",                                                                           |
|    |                |              |                |       "player._tag",                                                                         |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "name": "__AppendVertices_3",                                                            |
|    |                |              |                |     "type": "DATASET"                                                                        |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: __Filter_2                                                                         |
|    |                |              |                | space: 2                                                                                     |
|    |                |              |                | dedup: true                                                                                  |
|    |                |              |                | limit: 0                                                                                     |
|    |                |              |                | filter:                                                                                      |
|    |                |              |                | orderBy: []                                                                                  |
|    |                |              |                | src: $-._vid                                                                                 |
|    |                |              |                | props: [                                                                                     |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 4,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "name",                                                                                |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   },                                                                                         |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 3,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "name",                                                                                |
|    |                |              |                |       "age",                                                                                 |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   },                                                                                         |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 5,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "name",                                                                                |
|    |                |              |                |       "speciality",                                                                          |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | exprs:                                                                                       |
|    |                |              |                | vertex filter: (*.name=="Time Duncan")                                                       |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
|  9 | ScanVertices   | 0            |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "_vid",                                                                                |
|    |                |              |                |       "bachelor._tag",                                                                       |
|    |                |              |                |       "team._tag",                                                                           |
|    |                |              |                |       "player._tag"                                                                          |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "name": "__Filter_2",                                                                    |
|    |                |              |                |     "type": "DATASET"                                                                        |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: __VAR_0                                                                            |
|    |                |              |                | space: 2                                                                                     |
|    |                |              |                | dedup: false                                                                                 |
|    |                |              |                | limit: -1                                                                                    |
|    |                |              |                | filter: ((bachelor._tag IS NOT EMPTY OR team._tag IS NOT EMPTY) OR player._tag IS NOT EMPTY) |
|    |                |              |                | orderBy: []                                                                                  |
|    |                |              |                | props: [                                                                                     |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 5,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   },                                                                                         |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 4,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   },                                                                                         |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 3,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | exprs:                                                                                       |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
|  0 | Start          |              |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [],                                                                          |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__Start_0"                                                                      |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------

Mon, 20 Dec 2021 11:31:21 CST

There is a vertex filter *.name == 'Tim Duncan in AppendVertices node, it can't push down to storage. So limit can't push down too.

Shylock-Hg · 2021-12-20T03:36:43Z

See the case

nebula/tests/tck/features/match/Base.feature

Line 601 in e6ddeb2

"""

randomJoe211 · 2021-12-20T05:33:47Z

@Shylock-Hg Thanks for the reply. Yes, from the code's point of view, your answer may be logical. But such an answer cannot resolve the real issue, which is that the error code does not help uses to solve the problem.

Suppose you were a user, and after running a query you saw such an error code, wouldn't you modify the query according to the hint, add LIMIT and try again? And then you would find that it still reported the same error code. This is not right. @Sophie-Xie

whitewum · 2021-12-20T05:58:37Z

It's expected. See the execution plan:

Execution Plan (optimize time 2731 us)

-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
| id | name           | dependencies | profiling data | operator info                                                                                |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
|  7 | DataCollect    | 11           |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__DataCollect_7"                                                                |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: [                                                                                  |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__Limit_6"                                                                      |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | kind: ROW                                                                                    |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
| 11 | Project        | 10           |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__Limit_6"                                                                      |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: __Project_5                                                                        |
|    |                |              |                | columns: [                                                                                   |
|    |                |              |                |   "$-.v AS v"                                                                                |
|    |                |              |                | ]                                                                                            |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
| 10 | Limit          | 3            |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "_vid",                                                                                |
|    |                |              |                |       "bachelor._tag",                                                                       |
|    |                |              |                |       "team._tag",                                                                           |
|    |                |              |                |       "player._tag",                                                                         |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__Project_5"                                                                    |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: __AppendVertices_3                                                                 |
|    |                |              |                | offset: 0                                                                                    |
|    |                |              |                | count: 3                                                                                     |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
|  3 | AppendVertices | 9            |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "_vid",                                                                                |
|    |                |              |                |       "bachelor._tag",                                                                       |
|    |                |              |                |       "team._tag",                                                                           |
|    |                |              |                |       "player._tag",                                                                         |
|    |                |              |                |       "v"                                                                                    |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "name": "__AppendVertices_3",                                                            |
|    |                |              |                |     "type": "DATASET"                                                                        |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: __Filter_2                                                                         |
|    |                |              |                | space: 2                                                                                     |
|    |                |              |                | dedup: true                                                                                  |
|    |                |              |                | limit: 0                                                                                     |
|    |                |              |                | filter:                                                                                      |
|    |                |              |                | orderBy: []                                                                                  |
|    |                |              |                | src: $-._vid                                                                                 |
|    |                |              |                | props: [                                                                                     |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 4,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "name",                                                                                |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   },                                                                                         |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 3,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "name",                                                                                |
|    |                |              |                |       "age",                                                                                 |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   },                                                                                         |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 5,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "name",                                                                                |
|    |                |              |                |       "speciality",                                                                          |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | exprs:                                                                                       |
|    |                |              |                | vertex filter: (*.name=="Time Duncan")                                                       |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
|  9 | ScanVertices   | 0            |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [                                                                            |
|    |                |              |                |       "_vid",                                                                                |
|    |                |              |                |       "bachelor._tag",                                                                       |
|    |                |              |                |       "team._tag",                                                                           |
|    |                |              |                |       "player._tag"                                                                          |
|    |                |              |                |     ],                                                                                       |
|    |                |              |                |     "name": "__Filter_2",                                                                    |
|    |                |              |                |     "type": "DATASET"                                                                        |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | inputVar: __VAR_0                                                                            |
|    |                |              |                | space: 2                                                                                     |
|    |                |              |                | dedup: false                                                                                 |
|    |                |              |                | limit: -1                                                                                    |
|    |                |              |                | filter: ((bachelor._tag IS NOT EMPTY OR team._tag IS NOT EMPTY) OR player._tag IS NOT EMPTY) |
|    |                |              |                | orderBy: []                                                                                  |
|    |                |              |                | props: [                                                                                     |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 5,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   },                                                                                         |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 4,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   },                                                                                         |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "tagId": 3,                                                                              |
|    |                |              |                |     "props": [                                                                               |
|    |                |              |                |       "_tag"                                                                                 |
|    |                |              |                |     ]                                                                                        |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
|    |                |              |                | exprs:                                                                                       |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------
|  0 | Start          |              |                | outputVar: [                                                                                 |
|    |                |              |                |   {                                                                                          |
|    |                |              |                |     "colNames": [],                                                                          |
|    |                |              |                |     "type": "DATASET",                                                                       |
|    |                |              |                |     "name": "__Start_0"                                                                      |
|    |                |              |                |   }                                                                                          |
|    |                |              |                | ]                                                                                            |
-----+----------------+--------------+----------------+-----------------------------------------------------------------------------------------------

Mon, 20 Dec 2021 11:31:21 CST

There is a vertex filter *.name == 'Tim Duncan in AppendVertices node, it can't push down to storage. So limit can't push down too.

This is what you expected ???? ARE YOU SURE ???

Shylock-Hg · 2021-12-20T06:26:30Z

@Shylock-Hg Thanks for the reply. Yes, from the code's point of view, your answer may be logical. But such an answer cannot resolve the real issue, which is that the error code does not help uses to solve the problem.

Suppose you were a user, and after running a query you saw such an error code, wouldn't you modify the query according to the hint, add LIMIT and try again? And then you would find that it still reported the same error code. This is not right. @Sophie-Xie

The query like MATCH (v{name: "Tim Duncan"}) return v is in discussed, you could see the one proposal in #3255, how to handle the properties of vertex is not sure. So I don't process it in this PR too.

randomJoe211 · 2021-12-20T06:42:58Z

It's OK if Nebula Graph does not support MATCH (v{name: "Tim Duncan"}) return v.

The problem here is, running MATCH (v{name: "Tim Duncan"}) return v returns Scan edges must specify limit number, and if users follow this information and run MATCH (v{name: "Tim Duncan"}) return v LIMIT 10, it still shows Scan edges must specify limit number. It doesn't make any sense.

Again, it is OK if Nebula Graph does not support such a feature, but it cannot mislead users with such a wrong return. This is the real concern.

BTW, it is not related to any specific PR. I'm not saying that a certain PR created such an issue. I just hope that this issue can be resolved. For example:

Running MATCH (v{name: "Tim Duncan"}) return v returns xxx is not supported.
Or, Nebula Graph supports MATCH (v{name: "Tim Duncan"}) return v.
Or any other logical solution.

Shylock-Hg · 2021-12-20T08:29:34Z

In this case, we have two error:

match (v) return v , which don't specify limit
match (v{'name': 'Time Duncan'}) return v limit 3, which can't push down this limit

But in implementation, these two cases will be checked in same process. We could change error message to more friendly to user, but can't provide two error message.
WDYT?

randomJoe211 · 2021-12-20T09:27:36Z

What message do you plan to code?

Shylock-Hg · 2021-12-20T09:33:40Z

If want to provide two error message

What message do you plan to code?

Do you have suggestion?

randomJoe211 · 2021-12-20T09:47:15Z

If we can have two different messages for the two situations, then they may be To scan vertices, specify a LIMIT number. and Scanning by properties are not supported.

But if you wish to explain the two situations in one message, maybe To scan vertices, specify a LIMIT number. Scanning vertices by properties are not supported.? It's not a good error message. Do not use it unless you have no other solution. If you have to, I hope it is just a workaround, not the final solution.

Shylock-Hg · 2021-12-21T08:26:40Z

If we can have two different messages for the two situations, then they may be To scan vertices, specify a LIMIT number. and Scanning by properties are not supported.

But if you wish to explain the two situations in one message, maybe To scan vertices, specify a LIMIT number. Scanning vertices by properties are not supported.? It's not a good error message. Do not use it unless you have no other solution. If you have to, I hope it is just a workaround, not the final solution.

This error is not just for scan vertices and with properties, how about To scan vertices or edges need specify a LIMIT number, and LIMIT number need push down to scan.?

randomJoe211 · 2021-12-21T09:08:08Z

You decide.

randomJoe211 added the type/bug Type: something is unexpected label Dec 17, 2021

randomJoe211 mentioned this issue Dec 17, 2021

Questions for matching on edge types without indexes #3494

Closed

Sophie-Xie assigned CPWstatic Dec 17, 2021

Sophie-Xie added this to the v3.0.0 milestone Dec 17, 2021

Sophie-Xie assigned Shylock-Hg and Sophie-Xie and unassigned CPWstatic and Sophie-Xie Dec 17, 2021

jamieliu1023 mentioned this issue Dec 18, 2021

Weekly Report 2021-12-17 vesoft-inc/nebula-community#79

Closed

Shylock-Hg closed this as completed Dec 20, 2021

Sophie-Xie reopened this Dec 20, 2021

Shylock-Hg mentioned this issue Dec 23, 2021

Make scan limit error more friendly. #3549

Merged

7 tasks

yixinglu closed this as completed in #3549 Dec 28, 2021

jamieliu1023 mentioned this issue Jan 1, 2022

Weekly Report 2021-12-31 vesoft-inc/nebula-community#83

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Wrong error msg of matching on vertex properties #3492

Wrong error msg of matching on vertex properties #3492

randomJoe211 commented Dec 17, 2021 •

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Shylock-Hg commented Dec 21, 2021

randomJoe211 commented Dec 21, 2021

Wrong error msg of matching on vertex properties #3492

Wrong error msg of matching on vertex properties #3492

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randomJoe211 commented Dec 17, 2021 • edited Loading

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randomJoe211 commented Dec 20, 2021

Shylock-Hg commented Dec 20, 2021

randomJoe211 commented Dec 20, 2021

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randomJoe211 commented Dec 17, 2021 •

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Shylock-Hg commented Dec 20, 2021 •

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randomJoe211 commented Dec 20, 2021 •

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