Why call rows.Close() takes too long time when I call it after I exit from loop rows.Next() before processing all elements of loop.
Its happen when I make request which returns huge amount of data (around 300 000 rows).
This problem doesn't exists when amount of rows is not so big.
func SelectHugeAmountOfRows() {
query := `SELECT * FROM big_table`
rows, _ := Conn.Query(context.Background(), query)
defer func() {
fmt.Println("Start close rows")
start := time.Now()
rows.Close()
duration := time.Since(start)
fmt.Println("rowsClose duration:", duration)
}()
for rows.Next() {
rowValues, err := rows.Values()
if err != nil {
fmt.Println(err)
return
}
// do something with rowValues and get error in process
err = func() error {
fmt.Println(rowValues)
return errors.New("some error")
}()
if err != nil {
return
}
}
if err := rows.Err(); err != nil {
fmt.Println(err)
return
}
}
rowsClose duration: 1m2.5488669s
Interesting that duration of rows.Close() in this case in same as duration which I will have if will process all elements of rows.Next() loop without break it.
