Viewing profile — matc

> The application can move straight to supporting the new structure and entirely forget that the old one existed. Not always. Changing the schema can break an application, in parti…

The fact that ALTER TABLE locks on most databases is not the primary reason changing a schema is hard. The primary reason is that a schema change breaks the application [1]. Migrat…

Moving databases between clusters is no easy feat. Can you share more details on the man-hours it took to oversee and verify the migration? I see you mention several days for the d…

You can easily drop the oldest month every 1st using a delete statement. Queries can be fast with indexes without adding complexity.

If you are up for SQL, the downtime issue is solvable with ChronicDB pain-free.

1. Thank you for the link on views being updateable with some (natural) restrictions ( http://news.ycombinator.com/item?id=3406952 ). Given this feature, SQL offers the primitives …

You are right, this aspect is not new. More like half-baked. I'm not sure what you mean by bidirectional. If this suggests having a separate copy for the old data and the new data …

If you change the schema then the old version of the app can break. For example, if two tables are merged together. If one suggests old data and new data be stored separately then …

Views are the reflection of the light at the end of the tunnel, but solve less than half the problem to date. Views work on SELECT, but not on UPDATE/INSERT/DELETE. Also, what make…

This is what you are missing: > but that is always true You may have an old form you can't change. For example: - 10 apps connected to the same database. Changing the model breaks …

Schema-free != handling data model changes transparently.

We are actually working on this at ChronicDB http://chronicdb.com On 6ren's rigidity argument, relations and SQL are still not enough to guarantee you'll always be able to get the …

Agreed on backwards compatible, but for application semantics; not types of schema changes. There's no reason to not be allowed to both add and remove a column at the same time, or…

Why not?

There is no efficient safety interlock system when modifying data. Even if confident your test passed, what happens when you later realize it hadn't, and at what cost?

The denormalization argument is misguided. Denormalization is a performance consideration, and now even happens transparently at the storage layer in some RDBMs. So restructuring a…