Hacktoberfest 2026: the issues maintainers tagged for October, open and beginner-friendly. Browse Hacktoberfest issues

Segmentation fault

Open
  • Is something wrong?
#43 4 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
25/100
Issue type
Bug
Clarity
Needs clarification
Activity status
Stale
Tech stack
c
Domain
databases

Research direction

Reproduce the reported command and query against the same SQLAdvisor scenario, then inspect the path after step 5 when it runs explain select * from auth_function and crashes. The issue names no source file or test, so first locate the EXPLAIN and driver-table selection entry points. Done means the query no longer segfaults and the regression is covered by an appropriate test.

Written by the indexing model from the issue text.

Description

[root@qk-yunwei sqladvisor]# ./sqladvisor -h 192.168.1.XX -P 3306 -u XXX-p 'XXX' -d qk_auth -q "select af.* from auth_function af inner join auth_function_permission afp on af.id = afp.function_id where af.id=1;" -v 1
2017-07-28 15:44:12 1198 [Note] 2017-07-28 15:44:12 1198 [Note] 第2步：开始解析where中的条件:(af.id = 1)

2017-07-28 15:44:12 1198 [Note] show index from auth_function

2017-07-28 15:44:12 1198 [Note] show table status like 'auth_function'

2017-07-28 15:44:12 1198 [Note] select count(*) from ( select id from auth_function FORCE INDEX( PRIMARY ) order by id DESC limit 13) af where (af.id = 1)

2017-07-28 15:44:12 1198 [Note] 第3步：表auth_function的行数:27,limit行数:13,得到where条件中(af.id = 1)的选择度:13

2017-07-28 15:44:12 1198 [Note] 第4步：开始解析join on条件:af.id=afp.function_id

2017-07-28 15:44:12 1198 [Note] 第5步：开始选择驱动表,一共有2个候选驱动表

2017-07-28 15:44:12 1198 [Note] explain select * from auth_function

Segmentation fault

Dominant language
C
Stars
5.6k
Forks
1.2k
No merged PRs in 30d

Getting set up

This project ships no dev container, Dockerfile or contributing guide, so setting up is up to you: start from its README, and see our first-contribution guide for the general steps.

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

More from Meituan-Dianping/SQLAdvisor

All issues in Meituan-Dianping/SQLAdvisor

Similar issues

More C issues

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.