Can you explain what a deadlock is in databases?

A deadlock in databases is a situation where two or more processes (transactions) block resources needed by each other to continue working, and none of them can proceed.

Example: Transaction A has acquired resource 1 and is waiting for resource 2, while transaction B has acquired resource 2 and is waiting for resource 1. Neither can continue because each is waiting for the release of the other's resource.

In Go, when working with databases, this can manifest if multiple goroutines perform transactions simultaneously, blocking the same records or tables. To prevent deadlocks, it is important to design the order of resource acquisition correctly and to use timeouts or retries.