add content about lazy uniqueness check #10414

qiancai · 2022-09-14T01:49:18Z

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ti-chi-bot · 2022-09-14T01:49:19Z

[REVIEW NOTIFICATION]

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hfxsd

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constraints.md

error-codes.md

constraints.md

system-variables.md

constraints.md

error-codes.md

pessimistic-transaction.md

system-variables.md

qiancai · 2022-09-16T08:00:22Z

constraints.md


-{{< copyable "sql" >}}
+In optimistic transactions, TiDB checks unique constraints [lazily](/transaction-overview.md#lazy-check-of-constraints) by default. When an optimistic transaction is committed, TiDB performs a bulk check, which helps reduce network overhead and improve performance.


How about "When an optimistic transaction is committed, TiDB performs a batch check on unique constraints in this transaction, which helps reduce network overhead and improve performance."?

Can be "... by default, namely these checks are performed in the commit phase, which ..."

"namely these checks are performed in the commit phase" might give the confusion that "these checks are not performed in the execution phase"?

Emm you are right. Some checks could be performed in the execution phase. How about "some checks may be performed in the commit phase"?

It might be hard to know what are "some check may be", how about "By default, for optimistic transactions, TiDB checks unique constraints lazily in the execution phase and strictly in the commit phase, which helps reduce network overhead and improve performance."

Sounds OK to me

Co-authored-by: ekexium <eke@fastmail.com>

… into lazy-uniqueness-check

Co-authored-by: ekexium <eke@fastmail.com>

constraints.md

hfxsd

Rest LGTM

error-codes.md

hfxsd · 2022-09-16T13:37:48Z

system-variables.md

@@ -768,9 +768,10 @@ MPP is a distributed computing framework provided by the TiFlash engine, which a
 - Persists to cluster: Yes
 - Type: Boolean
 - Default value: `OFF`


Should off be 0?

OFF and 0 are equivalent.

system-variables.md

sticnarf

LGTM

constraints.md

system-variables.md

Co-authored-by: xixirangrang <hfxsd@hotmail.com>

… into lazy-uniqueness-check

Co-authored-by: xixirangrang <hfxsd@hotmail.com>

qiancai · 2022-09-19T03:45:13Z

/remove-status LGT1
/status LGT2

qiancai · 2022-09-19T03:45:24Z

/merge

ti-chi-bot · 2022-09-19T03:45:26Z

This pull request has been accepted and is ready to merge.

Commit hash: 143a9ee

qiancai added 2 commits September 12, 2022 19:52

Update constraints.md

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ti-chi-bot requested a review from shichun-0415 September 14, 2022 01:49

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qiancai added translation/from-docs-cn This PR is translated from a PR in pingcap/docs-cn. v6.3 This PR/issue applies to TiDB v6.3. labels Sep 14, 2022

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qiancai commented Sep 15, 2022

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Co-authored-by: ekexium <eke@fastmail.com>

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Merge branch 'lazy-uniqueness-check' of https://github.com/qiancai/docs…

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… into lazy-uniqueness-check

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Co-authored-by: ekexium <eke@fastmail.com>

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Co-authored-by: xixirangrang <hfxsd@hotmail.com>

change 0/1 to on/off

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… into lazy-uniqueness-check

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Co-authored-by: xixirangrang <hfxsd@hotmail.com>

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ti-chi-bot merged commit 285d36a into pingcap:master Sep 19, 2022


		{{< copyable "sql" >}}
		In optimistic transactions, TiDB checks unique constraints [lazily](/transaction-overview.md#lazy-check-of-constraints) by default. When an optimistic transaction is committed, TiDB performs a bulk check, which helps reduce network overhead and improve performance.

add content about lazy uniqueness check #10414

add content about lazy uniqueness check #10414

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First-time contributors' checklist

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qiancai commented Sep 19, 2022

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qiancai commented Sep 14, 2022 •

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