Write-through (cache policy in databases)

In business intelligence and data analytics, “write-through” is a type of caching policy used with databases to ensure that information is reliable and up-to-date. Imagine you’re writing a note to a friend and simultaneously sending them a text with the same message to make sure they get it right away—that’s kind of what write-through does with data. When an update or a new piece of data comes in, it is immediately saved in both the cache (a smaller, faster memory) and the underlying database storage.

This approach is super useful in situations where it’s crucial to have accurate data at all times, like in banking systems where account balances must always be correct. Write-through helps prevent data loss too. Since every change is instantly made in the main storage, even if something goes wrong with the cache, the data isn’t lost because it’s already been saved in the main database.

The main advantage of write-through caching is that it provides a high level of data integrity and consistency. However, because every write operation has to be completed in two places, it can sometimes slow things down compared to other caching policies where the data isn’t immediately saved to the main database. For businesses, choosing the right cache policy, like write-through, is about balancing the need for speed with the need for accurate and reliable data.