appview/db: improve repo-languages query #584

merged

opened by

oppi.li 2 months ago targeting master from push-xvuvxolnykpl

switch from corelated query to window function. practically, this gives us a 10x speedup for this portion of the function. we can go further by running each subquery for GetRepos concurrently, but the potential wins here is in the order of ~2ms.

Signed-off-by: oppiliappan me@oppi.li

options

unified split

Changed files

+13 -14

appview

repos.go

+13 -14

appview/db/repos.go

···

       131
        
       

     

       132
        
       	languageQuery := fmt.Sprintf(

     

       133
        
       		`

     

       134
       -
       		select

     

       135
       -
       			repo_at, language

     

       136
       -
       		from

     

       137
       -
       			repo_languages r1

     

       138
       -
       		where

     

       139
       -
       			repo_at IN (%s)

     

       0
        
       
     

       0
        
       
     

       0
        
       
     

       0
        
       
     

       0
        
       
     

       140
        
       			and is_default_ref = 1

     

       141
       -
       			and id = (

     

       142
       -
       				select id

     

       143
       -
       					from repo_languages r2

     

       144
       -
       					where r2.repo_at = r1.repo_at

     

       145
       -
       					and r2.is_default_ref = 1

     

       146
       -
       					order by bytes desc

     

       147
       -
       					limit 1

     

       148
       -
       			);

     

       149
        
       		`,

     

       150
        
       		inClause,

     

       151
        
       	)

···

       131
        
       

     

       132
        
       	languageQuery := fmt.Sprintf(

     

       133
        
       		`

     

       134
       +
       		select repo_at, language

     

       135
       +
       		from (

     

       136
       +
       			select

     

       137
       +
       			repo_at,

     

       138
       +
       			language,

     

       139
       +
       			row_number() over (

     

       140
       +
       				partition by repo_at

     

       141
       +
       				order by bytes desc

     

       142
       +
       			) as rn

     

       143
       +
       			from repo_languages

     

       144
       +
       			where repo_at in (%s)

     

       145
        
       			and is_default_ref = 1

     

       146
       +
       		)

     

       147
       +
       		where rn = 1

     

       0
        
       
     

       0
        
       
     

       0
        
       
     

       0
        
       
     

       0
        
       
     

       0
        
       
     

       148
        
       		`,

     

       149
        
       		inClause,

     

       150
        
       	)