5 ms·

AWS Database Migration Service (Preview)

49 points by runesoerensen 11y ago

Tomdarkness 11y ago
Wonder if it's possible to use this to upgrade Amazon RDS instances? At the moment you can't upgrade an existing postgres 9.3 RDS instance to 9.4 without dumping all the data and importing it into a new 9.4 RDS instance.
- dangrossman 11y ago
  That's possible according to the page: > AWS Database Migration Service can migrate on-premises databases to Amazon RDS or Amazon EC2, databases running on EC2 to RDS, or vice versa, as well as migrate an RDS database to another RDS database.
  - Tomdarkness 11y ago
    Excellent, will look forward to testing it out when it's available in eu-west-1. We'd like to use some of the new features in postgres 9.4 but our production DBs on RDS are stuck on 9.3 at the moment.
- znep 11y ago
  Sadly according to https://aws.amazon.com/dms/faqs/ https://aws.amazon.com/dms/faqs/ RDS SQL Server, RDS Postgres, and ODBC sources are supported in bulk extract mode only; the change data capture mode (CDC) is not yet supported. A shame since one of the biggest drawbacks to running postgres in RDS is getting the data out.
apetresc 11y ago
Genuinely curious how it's possible to port things like triggers from one engine to the next, when they may have fundamentally different syntax and semantics.
- cbsmith 11y ago
  That's been a "thing" for a while now. It's tricky, has some rough edges, but doable.
  - apetresc 11y ago
    Neat. How does it work? Like, do they compile one system's triggers to some sort of intermediate language, and then compile that back to the target system's language? Does the resulting code resemble something a human would write?
    - cbsmith 11y ago
      It's a combination of that (usually the intermediate language is ANSI SQL) and also used stored procs & UDT's to provide "work alike" behaviors.
wahnfrieden 11y ago
Does this help with online schema migrations too? Maybe for blue/green deployment of DB schema changes?
copsarebastards 11y ago
Currently 6 out of 30 links on HN are Amazon links, 4 of them in the top 5. Looks like someone paid for placement.

49 points by runesoerensen 11y ago

Wonder if it's possible to use this to upgrade Amazon RDS instances? At the moment you can't upgrade an existing postgres 9.3 RDS instance to 9.4 without dumping all the data and importing it into a new 9.4 RDS instance.

dangrossman 11y ago
That's possible according to the page: > AWS Database Migration Service can migrate on-premises databases to Amazon RDS or Amazon EC2, databases running on EC2 to RDS, or vice versa, as well as migrate an RDS database to another RDS database.
- Tomdarkness 11y ago
  Excellent, will look forward to testing it out when it's available in eu-west-1. We'd like to use some of the new features in postgres 9.4 but our production DBs on RDS are stuck on 9.3 at the moment.
znep 11y ago
Sadly according to https://aws.amazon.com/dms/faqs/ https://aws.amazon.com/dms/faqs/ RDS SQL Server, RDS Postgres, and ODBC sources are supported in bulk extract mode only; the change data capture mode (CDC) is not yet supported. A shame since one of the biggest drawbacks to running postgres in RDS is getting the data out.

apetresc 11y ago

Genuinely curious how it's possible to port things like triggers from one engine to the next, when they may have fundamentally different syntax and semantics.

cbsmith 11y ago
That's been a "thing" for a while now. It's tricky, has some rough edges, but doable.
- apetresc 11y ago
  Neat. How does it work? Like, do they compile one system's triggers to some sort of intermediate language, and then compile that back to the target system's language? Does the resulting code resemble something a human would write?
  - cbsmith 11y ago
    It's a combination of that (usually the intermediate language is ANSI SQL) and also used stored procs & UDT's to provide "work alike" behaviors.

wahnfrieden 11y ago

Does this help with online schema migrations too? Maybe for blue/green deployment of DB schema changes?

copsarebastards 11y ago

Currently 6 out of 30 links on HN are Amazon links, 4 of them in the top 5. Looks like someone paid for placement.