Optimize sqlutils.ToSqlite3Dialect for queries + DML/DDLs

[timvaillancourt]

Description

This PR adds some slight optimisations to sqlutils.ToSqlite3Dialect, a function we've noticed to take up a significant amount of CPU time in vtorc when it watches many instances, primarily due to large insert queries needing to be parsed by regexp filters

Profile SVG (need to enlarge):

All this change does is assumes inserts happen more frequently than alter/create. Moving inserts to be checked sooner and separating read queries causes them to have to go through fewer regex matches (still a lot 🙈). The expense of queries that are not insert, alter or create is unchanged.

On Slack's vtorc instances this gave us about a 15-20% reduction in user-CPU used by vtorc vs the previous avg

In the benchmark I added in the PR the difference is more like 8-9% for big inserts and 18-19% for reads

Before

goos: darwin
goarch: amd64
pkg: vitess.io/vitess/go/vt/external/golib/sqlutils
cpu: Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
BenchmarkToSqlite3Dialect_Insert1000
BenchmarkToSqlite3Dialect_Insert1000-16    	       1	1870643229 ns/op
BenchmarkToSqlite3Dialect_Select
BenchmarkToSqlite3Dialect_Select-16        	    3541	    330667 ns/op
PASS
ok  	vitess.io/vitess/go/vt/external/golib/sqlutils	4.660s

After

goos: darwin
goarch: amd64
pkg: vitess.io/vitess/go/vt/external/golib/sqlutils
cpu: Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
BenchmarkToSqlite3Dialect_Insert1000
BenchmarkToSqlite3Dialect_Insert1000-16    	       1	1711349181 ns/op
BenchmarkToSqlite3Dialect_Select
BenchmarkToSqlite3Dialect_Select-16        	    4436	    270223 ns/op
PASS
ok  	vitess.io/vitess/go/vt/external/golib/sqlutils	4.528s

Related Issue(s)

Resolves #17114

Checklist

• "Backport to:" labels have been added if this change should be back-ported to release branches
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• Tests were added or are not required
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• Documentation was added or is not required

Deployment Notes

[vitess-bot]

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[mattlord]

@GuptaManan100 do we still need this library at all? vtorc only supports SQLite now so I would think that we would use the SQLite dialect everywhere.

[timvaillancourt]

@GuptaManan100 do we still need this library at all? vtorc only supports SQLite now so I would think that we would use the SQLite dialect everywhere.

@mattlord this is what I asked/proposed in this thread 👍. I'm hoping we can remove dialect translation and just use sqlite dialect

Also I think external/sqlutils could be replaced with something a bit less crufty - there are similar projects that can reflect database/sql to map/structs for example. For now this is some duct tape

EDIT: an alternative I've enjoyed using is https://github.com/jmoiron/sqlx, but not sure how dependency-heavy it is. I'm 95% sure it will handle anything external/sqlutils provides and it's an active project. I can make that RFC and PRs if there is agreement

[dbussink]

@mattlord this is what I asked/proposed in this thread 👍. I'm hoping we can remove dialect translation and just use sqlite dialect

I think removing the translation and writing queries directly that work with sqlite is a good idea indeed. It removes this whole layer of translation that doesn't really serve any purpose anymore.

Also I think external/sqlutils could be replaced with something a bit less crufty - there are similar projects that can reflect database/sql to map/structs for example. For now this is some duct tape

I think it's a good idea to clean this up (also fine incrementally). It's all leftovers from how it was basically vendored but only parts have been modernized to match how other parts of Vitess work. So I think thinks kind of cleanup is also very welcome.

[codecov]

Codecov Report

Attention: Patch coverage is 83.33333% with 4 lines in your changes missing coverage. Please review.

Project coverage is 67.17%. Comparing base (fa5a2c5) to head (9e82f8b).
Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
go/vt/external/golib/sqlutils/sqlite_dialect.go	78.94%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #17113      +/-   ##
==========================================
- Coverage   67.17%   67.17%   -0.01%     
==========================================
  Files        1571     1571              
  Lines      252246   252258      +12     
==========================================
+ Hits       169458   169465       +7     
- Misses      82788    82793       +5     

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[GuptaManan100]

Yes, @timvaillancourt we can get rid of all other dialects other than sqlite. We don't allow any other backing database in VTOrc.

[timvaillancourt]

Closing in favour of #17124 which removes the translation entirely