What is phantom reading and lost write?

Phantom Read and Lost Update are issues related to concurrent transaction execution in databases.

Phantom Read occurs when a transaction executes a query that returns a set of rows, and then a subsequent query with the same conditions returns a different set of rows due to inserts or deletes by another transaction. In other words, data 'phantomly' appears or disappears between reads.

Lost Update is a situation where two transactions read the same data simultaneously, then both modify and write it back, with one transaction's changes overwriting the other's, resulting in lost data.

In Go (Golang), these problems are usually addressed at the database level by choosing appropriate transaction isolation levels and using locks. For example, when working with SQL databases via database/sql, you can manage transactions and set isolation levels to prevent phantom reads and lost updates.