Explain advanced database sharding strategies in large PHP systems.

Database sharding distributes data across multiple databases to improve scalability and throughput.

Single databases eventually become scalability bottlenecks because of:

Sharding horizontally partitions data across independent databases.

Sharding strategies:

Examples:

Simple but causes hotspot risks.

Uses hashing functions for balanced distribution.

Pros:

Cons:

Partitions by region.…