d29347220c
This changes ProjectsFinder#init_collection so it no longer relies on a
UNION. For example, to get starred projects of a user we used to run:
SELECT projects.*
FROM projects
WHERE projects.pending_delete = 'f'
AND (
projects.id IN (
SELECT projects.id
FROM projects
INNER JOIN users_star_projects
ON users_star_projects.project_id = projects.id
INNER JOIN project_authorizations
ON projects.id = project_authorizations.project_id
WHERE projects.pending_delete = 'f'
AND project_authorizations.user_id = 1
AND users_star_projects.user_id = 1
UNION
SELECT projects.id
FROM projects
INNER JOIN users_star_projects
ON users_star_projects.project_id = projects.id
WHERE projects.visibility_level IN (20, 10)
AND users_star_projects.user_id = 1
)
)
ORDER BY projects.id DESC;
With these changes the above query is turned into the following instead:
SELECT projects.*
FROM projects
INNER JOIN users_star_projects
ON users_star_projects.project_id = projects.id
WHERE projects.pending_delete = 'f'
AND (
EXISTS (
SELECT 1
FROM project_authorizations
WHERE project_authorizations.user_id = 1
AND (project_id = projects.id)
)
OR projects.visibility_level IN (20,10)
)
AND users_star_projects.user_id = 1
ORDER BY projects.id DESC;
This query in turn produces a better execution plan and takes less time,
though the difference is only a few milliseconds (this however depends
on the amount of data involved and additional conditions that may be
added).
5 lines
134 B
YAML
5 lines
134 B
YAML
---
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title: Refactor ProjectsFinder#init_collection to produce more efficient queries for
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retrieving projects
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merge_request:
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author:
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