In PHP, what are some alternative methods for marking messages as read or unread without impacting performance for a large number of users?

When dealing with a large number of users, marking messages as read or unread can impact performance if done inefficiently. One alternative method is to store the read/unread status in a separate table or column, rather than updating the message itself. This way, you can quickly query the status without affecting the original message data. 

// Example of storing read/unread status in a separate table

// Assuming you have a messages table with columns: id, message
// And a read_status table with columns: id, message_id, user_id, is_read

// When a user reads a message
$userId = 1;
$messageId = 123;

// Check if the read_status record exists
$existingStatus = $db->query("SELECT * FROM read_status WHERE message_id = $messageId AND user_id = $userId")->fetch();

if (!$existingStatus) {
    // Create a new read_status record
    $db->query("INSERT INTO read_status (message_id, user_id, is_read) VALUES ($messageId, $userId, 1)");
}

// When checking if a message is read
$isRead = $db->query("SELECT is_read FROM read_status WHERE message_id = $messageId AND user_id = $userId")->fetchColumn();

if ($isRead) {
    // Message is read
} else {
    // Message is unread
}

Keywords

MySQL indexing caching Redis message status.

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