lewis.moe
Monorepo for Tangled
appview/db: improve repo-languages query
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>
authored by
oppiliappan
and committed by
Tangled
8dca6c02
af39fa77
+13
-14
appview/db/repos.go
+13
-14
appview/db/repos.go
···
131
131
132
132
languageQuery := fmt.Sprintf(
133
133
`
134
-
select
135
-
repo_at, language
136
-
from
137
-
repo_languages r1
138
-
where
139
-
repo_at IN (%s)
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)
140
145
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
-
);
146
+
)
147
+
where rn = 1
149
148
`,
150
149
inClause,
151
150
)