sys var: add tidb_enable_shared_lock_promotion related doc change
#18229
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Signed-off-by: cfzjywxk <cfzjywxk@gmail.com>
joey-yez
reviewed
Aug 2, 2024
system-variables.md
Outdated
| - 是否持久化到集群：是 | ||
| - 类型：布尔型 | ||
| - 默认值：`OFF` | ||
| - 该变量用于控制是否启用共享锁升级为排他锁的功能。当该变量值为 `ON` 时，TiDB 会尝试将共享锁升级为排他锁，以减少死锁的概率。该变量默认值为 `OFF`，表示不启用共享锁升级为排他锁的功能。注意该变量不可和 [`tidb_enable_noop_functions`](#tidb_enable_noop_functions-span-classversion-mark从-v40-版本开始引入span) 同时开启。 |
Signed-off-by: cfzjywxk <cfzjywxk@gmail.com>
2da0067 to
5c9e67e
Compare
hfxsd
reviewed
Aug 2, 2024
hfxsd
reviewed
Aug 2, 2024
hfxsd
reviewed
Aug 2, 2024
hfxsd
reviewed
Aug 2, 2024
hfxsd
reviewed
Aug 2, 2024
tidb_enable_shared_lock_upgrade related doc change
17 tasks
Co-authored-by: xixirangrang <hfxsd@hotmail.com>
Co-authored-by: xixirangrang <hfxsd@hotmail.com>
MyonKeminta
reviewed
Aug 6, 2024
pessimistic-transaction.md
Outdated
| 使用这个语句执行的时候，效果和没有加锁是一样的，不会阻塞其他事务的读写。 | ||
| TiDB 默认不支持 `SELECT LOCK IN SHARE MODE`。 | ||
|
|
||
| 从 v8.3.0 版本开始，TiDB 支持使用 [`tidb_enable_shared_lock_upgrade`](/system-variables.md#tidb_enable_shared_lock_upgrade-span-classversion-mark从-v830-版本开始引入span) 系统变量开启 `SELECT LOCK IN SHARE MODE` 语句的功能。开启后，`SELECT LOCK IN SHARE MODE` 语句会升级为 `SELECT FOR UPDATE` 语句，对数据行加悲观锁。 |
There was a problem hiding this comment.
有点担心表述可能造成误解，是不是最好直接说 SELECT LOCK IN SHARE MODE 会进行等同于 SELECT FOR UPDATE 的行为，而不是先说启用 SELECT LOCK IN SHARE MODE 的功能、后面再补充解释比较好？另外后面的“升级”这个表述感觉对用户来说可能也不是很好理解
MyonKeminta
reviewed
Aug 6, 2024
MyonKeminta
reviewed
Aug 6, 2024
Co-authored-by: MyonKeminta <9948422+MyonKeminta@users.noreply.github.com>
Co-authored-by: MyonKeminta <9948422+MyonKeminta@users.noreply.github.com>
|
@joey-yez PTAL again |
hfxsd
reviewed
Aug 6, 2024
hfxsd
reviewed
Aug 8, 2024
hfxsd
reviewed
Aug 8, 2024
tidb_enable_shared_lock_upgrade related doc changetidb_enable_shared_lock_promotion related doc change
hfxsd
reviewed
Aug 14, 2024
lilin90
reviewed
Aug 15, 2024
lilin90
reviewed
Aug 15, 2024
Co-authored-by: Lilian Lee <lilin@pingcap.com>
Co-authored-by: Lilian Lee <lilin@pingcap.com>
Co-authored-by: Lilian Lee <lilin@pingcap.com>
hfxsd
reviewed
Aug 15, 2024
hfxsd
reviewed
Aug 15, 2024
|
/approve |
|
[APPROVALNOTIFIER] This PR is APPROVED This pull-request has been approved by: hfxsd The full list of commands accepted by this bot can be found here. The pull request process is described here
Needs approval from an approver in each of these files:
Approvers can indicate their approval by writing |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
First-time contributors' checklist
What is changed, added or deleted? (Required)
Referenced tidb issue pingcap/tidb#55022, the document for supporting upgrading
for sharelock statement tofor updatestatement.Which TiDB version(s) do your changes apply to? (Required)
Tips for choosing the affected version(s):
By default, CHOOSE MASTER ONLY so your changes will be applied to the next TiDB major or minor releases. If your PR involves a product feature behavior change or a compatibility change, CHOOSE THE AFFECTED RELEASE BRANCH(ES) AND MASTER.
For details, see tips for choosing the affected versions (in Chinese).
What is the related PR or file link(s)?
Do your changes match any of the following descriptions?