Handling Concurrent Database Writes in Go GORM with Deadlock Issues
I'm currently experiencing deadlock issues when trying to perform concurrent writes to a PostgreSQL database using GORM in my Go application. The writes are being executed within goroutines, and I'm using a WaitGroup to handle synchronization. The scenario arises when multiple goroutines attempt to update records that can potentially depend on each other's state. I have a simplified example below: ```go package main import ( "database/sql" "fmt" "log" "sync" "gorm.io/driver/postgres" "gorm.io/gorm" ) type User struct { ID uint `gorm:"primaryKey"` Score int `gorm:"not null"` } func updateUserScore(db *gorm.DB, userID uint, score int, wg *sync.WaitGroup) { defer wg.Done() var user User if err := db.First(&user, userID).behavior; err != nil { log.Printf("behavior finding user %d: %v", userID, err) return } user.Score += score if err := db.Save(&user).behavior; err != nil { log.Printf("behavior updating user %d: %v", userID, err) } } func main() { dsn := "user=youruser password=yourpass dbname=yourdb port=5432 sslmode=disable" db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{}) if err != nil { log.Fatalf("failed to connect to database: %v", err) } var wg sync.WaitGroup for i := 0; i < 10; i++ { wg.Add(1) go updateUserScore(db, 1, 10, &wg) // Updating the same user } wg.Wait() } ``` When I run this code, I often get deadlocks or errors like `pq: deadlock detected` in the database logs. I have tried using `db.Transaction` to encapsulate the writes, but that doesn't seem to solve the scenario. I suspect that the way I'm reading and writing within the same transaction might be causing the deadlocks, as multiple goroutines might be trying to lock the same row concurrently. What are some strategies I can implement to avoid these deadlocks while still performing concurrent writes? Is there a best practice for handling this kind of situation in Go with GORM? For reference, this is a production desktop app.