add document for explain/explain analyze of mpp query. #5754

windtalker · 2021-03-17T04:50:48Z

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This pr add document for explain/explain analyze of mpp query.

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windtalker · 2021-03-17T04:56:13Z

/cc @ilovesoup

TomShawn · 2021-03-17T06:21:07Z

/label needs-cherry-pick-5.0

TomShawn · 2021-03-17T06:22:43Z

/status PTAL
/size large
/translation doing
/assign
/cc XuHuaiyu

TomShawn · 2021-03-17T06:23:13Z

/label v5.0

TomShawn · 2021-03-18T06:26:11Z

TOC.md

@@ -102,6 +102,14 @@
    + [SQL 性能调优概览](/sql-tuning-overview.md)
    + 理解 TiDB 执行计划
      + [TiDB 执行计划概览](/explain-overview.md)
+      + [TiDB 执行计划 walkthrough](/explain-walkthrough.md)


These documents are added to TOC in https://github.com/pingcap/docs-cn/pull/5561/files. PTAL

OK, I will delete these change in my PR, but when will that pr be merged? Looks like no one has dealt with that pr for 11 days.

What about using the added TOC entries in #5561 without waiting for #5561's merge? Personally, I think they are more expressive. If you think any modification is needed, feel free to apply it.

You mean not change TOC.md in this pr, just updating #5561 after this pr is merged?

Or maybe just merge this pr, and let the owner of #5561 to resolve the conflict?

"You mean not change TOC.md in this pr, just updating #5561 after this pr is merged?"

Good idea! We just need to add "TiDB mpp 执行计划" in this PR and leave other things to 5561. So this PR is not blocked by 5561.

OK, I've remove TOC related changes, I think it is ready to be merged, PTAL

No. You still need to add this doc to TOC in this PR. Otherwise, users cannot find this doc on the left navigation menu of the PingCAP doc site. What about MPP 模式查询的执行计划？

ilovesoup · 2021-03-18T08:48:58Z

explain-mpp.md

+------------------------------------+---------+---------+-------------------+---------------+---------------------------------------------------------------------------------------------+----------------------------------------------------------------+--------+------+
+```
+
+与 explain 相比，ExchangeSender 的 operator info 中多了 task id 的输出，其记录了该 query fragment 实例化成的 MPP Task 的 task id，此外 MPP Executor 中都会有 `threads` 这一列，这列记录了 MPP 在执行该算子时使用的并发数（对于有多个节点组成的集群，改并发数是所有节点并发数相加的结果）。


Please provide an sample of join.

@windtalker, we need to complete the CN docs today. PTAL, thanks!

You mean this pr should be merged today? Currently it is blocked by #5702 and #5561

It's not blocked by #5561. For #5702, the content is ready for merge. This PR should be merged after #5702.

ilovesoup

LGTM except need an sample of join with shuffle.

ti-chi-bot · 2021-03-18T08:49:19Z

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LGTM except need an sample of join with shuffle.

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XuHuaiyu · 2021-03-18T09:38:51Z

/lgtm

ti-chi-bot · 2021-03-18T09:38:53Z

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windtalker · 2021-03-19T02:04:00Z

Currently blocked by #5702 and #5561

explain-mpp.md

TomShawn · 2021-03-19T10:54:15Z

explain-mpp.md

+------------------------------------+---------+---------+-------------------+---------------+---------------------------------------------------------------------------------------------+----------------------------------------------------------------+--------+------+
+```
+
+与 explain 相比，ExchangeSender 的 operator info 中多了 task id 的输出，其记录了该 query fragment 实例化成的 MPP Task 的 task id，此外 MPP Executor 中都会有 `threads` 这一列，这列记录了 MPP 在执行该算子时使用的并发数（对于有多个节点组成的集群，改并发数是所有节点并发数相加的结果）。


It's not blocked by #5561. For #5702, the content is ready for merge. This PR should be merged after #5702.

TomShawn · 2021-03-19T11:42:57Z

explain-mpp.md

+SET tidb_allow_mpp = 1;
+```
+
+## MPP query fragment 和 MPP task


是否有对应的中文写法？比如 MPP 查询分片，MPP 任务？

有的，我改一下

explain-mpp.md

TomShawn · 2021-03-19T12:23:50Z

explain-mpp.md

+------------------------------------+---------+---------+-------------------+---------------+---------------------------------------------------------------------------------------------+----------------------------------------------------------------+--------+------+
+```
+
+与 explain 相比，ExchangeSender 的 operator info 中多了 task id 的输出，其记录了该 query fragment 实例化成的 MPP Task 的 task id，此外 MPP Executor 中都会有 `threads` 这一列，这列记录了 MPP 在执行该算子时使用的并发数（对于有多个节点组成的集群，改并发数是所有节点并发数相加的结果）。


Suggested change

与 explain 相比，ExchangeSender 的 operator info 中多了 task id 的输出，其记录了该 query fragment 实例化成的 MPP Task 的 task id，此外 MPP Executor 中都会有 `threads` 这一列，这列记录了 MPP 在执行该算子时使用的并发数（对于有多个节点组成的集群，改并发数是所有节点并发数相加的结果）。

与 `EXPLAIN` 的输出结果相比，ExchangeSender 的 operator info 列中多了 task id 的输出，记录了该 query fragment 实例化成的 MPP Task 的 task id。此外 MPP Operator 中都会有 `threads` 这一列，这列记录了 MPP 在执行该算子时使用的并发数（对于由多个节点组成的集群，该并发数是所有节点并发数相加的结果）。

TomShawn · 2021-03-19T12:26:56Z

/remove-status PTAL
/status require-change

ti-chi-bot · 2021-03-23T09:40:51Z

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TomShawn · 2021-03-23T11:03:55Z

/remove-status require-change

TomShawn · 2021-03-24T02:06:55Z

/unassign
/assign @CharLotteiu

TomShawn · 2021-03-24T06:07:45Z

/label require-LGT1

TomShawn · 2021-03-24T06:07:52Z

/merge

ti-chi-bot · 2021-03-24T06:07:54Z

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

Commit hash: 52bd904

XuHuaiyu · 2021-03-24T07:27:50Z

/lgtm

ti-chi-bot · 2021-03-24T07:27:51Z

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TomShawn · 2021-03-24T07:35:54Z

/merge

ti-chi-bot · 2021-03-24T07:35:56Z

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

Commit hash: 870bb10

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

ti-srebot · 2021-03-24T07:38:10Z

cherry pick to release-5.0 in PR #5825

CharLotteiu · 2021-03-25T12:28:55Z

/remove-translation doing
/translation done

TomShawn · 2021-03-26T06:43:24Z

explain-mpp.md

+{{< copyable "sql" >}}
+
+```sql
+SET tidb_opt_broadcast_join=0; SET tidb_broadcast_join_threshold_count=0; SET tidb_broadcast_join_threshold_size=0; EXPLAIN SELECT COUNT(*) FROM t1 a JOIN t1 b ON a.id = b.id;


SET tidb_opt_broadcast_join=0;
SET tidb_broadcast_join_threshold_count=0;
SET tidb_broadcast_join_threshold_size=0;
EXPLAIN SELECT COUNT(*) FROM t1 a JOIN t1 b ON a.id = b.id;

add explain/explain analyze for mpp

03e72e7

ti-chi-bot added missing-translation-status This PR does not have translation status info. size/L Denotes a PR that changes 100-499 lines, ignoring generated files. labels Mar 17, 2021

windtalker changed the title ~~add explain/explain analyze for mpp~~ add document for explain/explain analyze of mpp query. Mar 17, 2021

ti-chi-bot requested a review from ilovesoup March 17, 2021 04:56

ti-chi-bot added the needs-cherry-pick-5.0 label Mar 17, 2021

ti-chi-bot assigned TomShawn Mar 17, 2021

ti-chi-bot added status/PTAL This PR is ready for reviewing. size/large Changes of a large size. labels Mar 17, 2021

ti-chi-bot requested a review from XuHuaiyu March 17, 2021 06:22

ti-chi-bot added translation/doing This PR’s assignee is translating this PR. and removed missing-translation-status This PR does not have translation status info. labels Mar 17, 2021

ti-chi-bot added the v5.0 This PR/issue applies to TiDB v5.0 label Mar 17, 2021

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address comments

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ti-chi-bot removed the size/large Changes of a large size. label Mar 19, 2021

move this change to pingcap#5561

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ti-chi-bot assigned CharLotteiu and unassigned TomShawn Mar 24, 2021

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Merge branch 'master' of github.com:pingcap/docs-cn into explain_mpp

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ti-chi-bot added the status/can-merge Indicates a PR has been approved by a committer. label Mar 24, 2021

ti-chi-bot merged commit a45c36a into pingcap:master Mar 24, 2021

ti-srebot pushed a commit to ti-srebot/docs-cn that referenced this pull request Mar 24, 2021

cherry pick pingcap#5754 to release-5.0

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Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

ti-srebot mentioned this pull request Mar 24, 2021

add document for explain/explain analyze of mpp query. (#5754) #5825

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ti-chi-bot pushed a commit that referenced this pull request Mar 24, 2021

add document for explain/explain analyze of mpp query. (#5754) (#5825)

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CharLotteiu mentioned this pull request Mar 25, 2021

EXPLAIN: add document for explain/explain analyze of mpp query pingcap/docs#5123

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ti-chi-bot added translation/done This PR has been translated from English into Chinese and updated to pingcap/docs-cn in a PR. and removed translation/doing This PR’s assignee is translating this PR. labels Mar 25, 2021

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ti-srebot mentioned this pull request Mar 29, 2021

EXPLAIN: add document for explain/explain analyze of mpp query (#5123) pingcap/docs#5142

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	与 explain 相比，ExchangeSender 的 operator info 中多了 task id 的输出，其记录了该 query fragment 实例化成的 MPP Task 的 task id，此外 MPP Executor 中都会有 `threads` 这一列，这列记录了 MPP 在执行该算子时使用的并发数（对于有多个节点组成的集群，改并发数是所有节点并发数相加的结果）。
	与 `EXPLAIN` 的输出结果相比，ExchangeSender 的 operator info 列中多了 task id 的输出，记录了该 query fragment 实例化成的 MPP Task 的 task id。此外 MPP Operator 中都会有 `threads` 这一列，这列记录了 MPP 在执行该算子时使用的并发数（对于由多个节点组成的集群，该并发数是所有节点并发数相加的结果）。

add document for explain/explain analyze of mpp query. #5754

add document for explain/explain analyze of mpp query. #5754

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windtalker commented Mar 17, 2021 • edited Loading

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windtalker commented Mar 17, 2021

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"You mean not change TOC.md in this pr, just updating #5561 after this pr is merged?"

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windtalker commented Mar 17, 2021 •

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