pingcap / pingcap/tiflash

Investigate optimization opportunities of reading tables with clustered index enabled.

Open
#1,438 0 comments 0 reactions 1 assignee View on GitHub

@flowbehappy is already working on this.

Since Feb 19, 2021.

Dominant language
C++
Stars
1k
Forks
423
Avg merge
1d 15h
Merged PRs (30d)
24

Description

In a real-world case, we found the performance of "ºcount(*)" drop by 4 times.

mysql> select count(*) from cmdb_rel_ci;
+-----------+
| count(*)  |
+-----------+
| 101000000 |
+-----------+
1 row in set (0.28 sec)
mysql> select count(*) from cmdb_rel_ci_clidx;
+-----------+
| count(*)  |
+-----------+
| 101000000 |
+-----------+
1 row in set (1.30 sec) 

Contributor guide

No contributing guide indexed for this repository

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.

Assessment

This issue has not been assessed yet.

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.