Should You Use Persistent Connections in PDO?

Drawbacks of Persistent Connections in PDO

While persistent connections in PDO promise speed improvements, it is crucial to be aware of their potential drawbacks.

One significant issue with persistent connections arises from the non-termination of connections when scripts abruptly end. This can have severe consequences, such as:

• Locked Tables: If a dead script locks tables, those tables remain locked until the connection terminates or another script unlocks them.
• Transaction Obstruction: Uncommitted transactions from dead scripts can block tables until the deadlock timer triggers, potentially killing the newer request instead of the older one.
• Inconsistent Transaction States: The next script that retrieves a connection after a dead script may inherit the previous transaction state, leading to incorrect commits or rollbacks.

These problems can significantly impact application performance and stability, especially in cases where scripts experience frequent unexpected terminations.

Additionally, persistent connections conflict with connection pooling mechanisms in modern databases like PostgreSQL. Using database-specific connection pooling ensures reliability and avoids the potential pitfalls associated with PDO persistent connections.

While persistent connections may have performance advantages, it is essential to consider their potential drawbacks. Unless creating database connections is a proven bottleneck, it is generally advisable to refrain from using persistent connections.

The above is the detailed content of Should You Use Persistent Connections in PDO?. For more information, please follow other related articles on the PHP Chinese website!