The document discusses ways to scale PHP applications. It covers using indexes, vertical partitioning, replication, load balancing, and storing sessions in a database table to allow sharing session data across multiple servers. Vertical partitioning involves splitting tables across multiple database servers based on certain columns like ID ranges, lists of values, or hashing on columns. Load balancing can be done at the web server level using modules like mod_proxy and mod_rewrite to route requests to read or write servers. Storing sessions in a database table allows session data to be shared between servers.
The document discusses ways to scale PHP applications. It covers using indexes, vertical partitioning, replication, load balancing, and storing sessions in a database table to allow sharing session data across multiple servers. Vertical partitioning involves splitting tables across multiple database servers based on certain columns like ID ranges, lists of values, or hashing on columns. Load balancing can be done at the web server level using modules like mod_proxy and mod_rewrite to route requests to read or write servers. Storing sessions in a database table allows session data to be shared between servers.