Performance regression by pr/33861

[tiancaiamao]

Enhancement

Found by #25754
See http://www.zenlife.tk:18081/alloc

[tiancaiamao]

cd session
go test -run TestXX -bench BenchmarkExplainTableLookup -benchmem

Before #33861

BenchmarkExplainTableLookup-16    	   42543	     27101 ns/op	   15505 B/op	     198 allocs/op

and After

BenchmarkExplainTableLookup-16    	   38823	     29272 ns/op	   16636 B/op	     219 allocs/op

You can also use some other function like BenchmarkBatchPointGet BenchmarkPointGet

[mornyx]

Should be the same as #34525.

The green part should be covered by #34558, but the blue part is still not clear.

Please help confirm why the stmtsummary module is taking a lot of memory and whether this is expected. cc @crazycs520

[tiancaiamao]

@mornyx As far as I know, stmtsummary is always a large part of the object allocating...
It's not a regression, it's something just always there (maybe we should optimize it)

[mornyx]

As far as I know, stmtsummary is always a large part of the object allocating... It's not a regression, it's something just always there (maybe we should optimize it)

Got it, thanks~