Add index to issue_user.issue_id (#27154) (#27158)

Backport #27154 by @JakobDev

This fixes a performance bottleneck. It was discovered by Codeberg.
Every where query on that table (which has grown big over time) uses
this column, but there is no index on it.

See this part of the log which was posted on Matrix:
```
2023/09/10 00:52:01 ...rs/web/repo/issue.go:1446:ViewIssue() [W] [Slow SQL Query] UPDATE `issue_user` SET is_read=? WHERE uid=? AND issue_id=? [true x y] - 51.395434887s
2023/09/10 00:52:01 ...rs/web/repo/issue.go:1447:ViewIssue() [E] ReadBy: Error 1205 (HY000): Lock wait timeout exceeded; try restarting transaction
2023/09/10 00:52:01 ...eb/routing/logger.go:102:func1() [I] router: completed GET /Codeberg/Community/issues/1201 for [::ffff:xxx]:0, 500 Internal Server Error in 52384.2ms @ repo/issue.go:1256(repo.ViewIssue)
```

Co-authored-by: JakobDev <jakobdev@gmx.de>
This commit is contained in:
Giteabot 2023-09-21 11:42:34 +08:00 committed by GitHub
parent 707c69f399
commit c3b7120042
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3 changed files with 19 additions and 1 deletions

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@ -15,7 +15,7 @@ import (
type IssueUser struct {
ID int64 `xorm:"pk autoincr"`
UID int64 `xorm:"INDEX"` // User ID.
IssueID int64
IssueID int64 `xorm:"INDEX"`
IsRead bool
IsMentioned bool
}

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@ -534,6 +534,8 @@ var migrations = []Migration{
NewMigration("Add ScheduleID for ActionRun", v1_21.AddScheduleIDForActionRun),
// v276 -> v277
NewMigration("Add RemoteAddress to mirrors", v1_21.AddRemoteAddressToMirrors),
// v277 -> v278
NewMigration("Add Index to issue_user.issue_id", v1_21.AddIndexToIssueUserIssueID),
}
// GetCurrentDBVersion returns the current db version

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@ -0,0 +1,16 @@
// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package v1_21 //nolint
import (
"xorm.io/xorm"
)
func AddIndexToIssueUserIssueID(x *xorm.Engine) error {
type IssueUser struct {
IssueID int64 `xorm:"INDEX"`
}
return x.Sync(new(IssueUser))
}