Projection pushdown to tikv feature GA - Githubissues

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Projection pushdown to tikv feature GA #51876

Open yibin87 opened 5 months ago

yibin87 commented 5 months ago

Enhancement

tidb_opt_projection_push_down is introduced by #27029 , and is set 'off' by default, still not GA now. It aimed to improve performance in two sides:

Utilize distributed tikv nodes to perform calculations parallelly
Provide an elegantly way to reduce unused columns which are transformed back to tidb from tikv #44902

However, there are still some basic functionality issues when this feature is set 'on':

[x] #34993
[x] #51874

Also exposed some existing function behavior inconsistency issues:

[x] #51877
[x] #51879
[x] #51880
[x] #51881
[ ] #51882

And after these functionality issues are fixed, we need to consider the performance impact

[x] #53613

Others:

[x] #53831
[x] https://github.com/PingCAP-QE/tidb-test/pull/2348
[x] https://github.com/pingcap/docs-cn/pull/17891

yibin87 commented 5 months ago

/assign @yibin87