[bugfix] Fix slow joined home timeline query (#1867)

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tobi 2023-06-04 21:17:28 +02:00 committed by GitHub
parent 45773a0bf4
commit d7d660374a
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1 changed files with 15 additions and 17 deletions

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@ -53,15 +53,7 @@ func (t *timelineDB) GetHomeTimeline(ctx context.Context, accountID string, maxI
NewSelect(). NewSelect().
TableExpr("? AS ?", bun.Ident("statuses"), bun.Ident("status")). TableExpr("? AS ?", bun.Ident("statuses"), bun.Ident("status")).
// Select only IDs from table // Select only IDs from table
Column("status.id"). Column("status.id")
// Find out who accountID follows.
Join("LEFT JOIN ? AS ? ON ? = ? AND ? = ?",
bun.Ident("follows"),
bun.Ident("follow"),
bun.Ident("follow.target_account_id"),
bun.Ident("status.account_id"),
bun.Ident("follow.account_id"),
accountID)
if maxID == "" || maxID >= id.Highest { if maxID == "" || maxID >= id.Highest {
const future = 24 * time.Hour const future = 24 * time.Hour
@ -109,15 +101,21 @@ func (t *timelineDB) GetHomeTimeline(ctx context.Context, accountID string, maxI
q = q.Order("status.id ASC") q = q.Order("status.id ASC")
} }
// Use a WhereGroup here to specify that we want EITHER statuses posted by accounts that accountID follows, // Subquery to select target (followed) account
// OR statuses posted by accountID itself (since a user should be able to see their own statuses). // IDs from follows owned by given accountID.
// subQ := t.conn.
// This is equivalent to something like WHERE ... AND (... OR ...) NewSelect().
// See: https://bun.uptrace.dev/guide/queries.html#select TableExpr("? AS ?", bun.Ident("follows"), bun.Ident("follow")).
q = q.WhereGroup(" AND ", func(*bun.SelectQuery) *bun.SelectQuery { Column("follow.target_account_id").
Where("? = ?", bun.Ident("follow.account_id"), accountID)
// Use the subquery in a WhereGroup here to specify that we want EITHER
// - statuses posted by accountID itself OR
// - statuses posted by accounts that accountID follows
q = q.WhereGroup(" AND ", func(q *bun.SelectQuery) *bun.SelectQuery {
return q. return q.
WhereOr("? = ?", bun.Ident("follow.account_id"), accountID). Where("? = ?", bun.Ident("status.account_id"), accountID).
WhereOr("? = ?", bun.Ident("status.account_id"), accountID) WhereOr("? IN (?)", bun.Ident("status.account_id"), subQ)
}) })
if err := q.Scan(ctx, &statusIDs); err != nil { if err := q.Scan(ctx, &statusIDs); err != nil {