Infrastructure at your Service
A common issue with insert only tables in PostgreSQL is, that autovacuum well never kick in as the formula for autovacuum considers obsoleted tuples since the last vacuum but not the number of inserted tuples. Because of this you usually run a manual vacuum when a table is bulk loaded right after the load or you schedule regular vacuums for tables you know are insert only. PostgreSQL 13 will finally solve that issue because autovacuum…
In the last post we had a look on how you can use AWS Storage Gateway as File gateway to store your PostgreSQL backups safely offsite on AWS S3. Another method of doing that would be to use “Cached Volume gateway” instead of the File gateway we used in the last post. The volume gateways does not provide access via NFS or SMB but does provide a volume over iSCSI and the on-prem machines will…
In the last post we had a quick look at AWS Kinesis data streams and how you can push data to AWS S3 using AWS Firehose. Another great AWS service is AWS Storage Gateway and in this post we’ll use that to push our PostgreSQL backups to AWS. The primary usage of AWS Storage Gateway is to extend you local storage to AWS so that you do not have to extend your local storage on…
Before we really start with this post: This is just an experiment and you should not implement it like this in real life. The goal of this post is just to show what is possible and I am not saying that you should do it (the way it is implemented here will be catastrophic for your database performance and it is not really secure). As I am currently exploring a lot of AWS services I…
When you start to write business logic in the database by using triggers or functions/procedures you usually want to report messages to the user that runs your code or you want to include some debugging output for your own. In Oracle a lot of people use the dbms_output package to return simple messages to the user’s screen. In PostgreSQL you can do the same but of course the way it is implemented is not the…
This is the last post in this little series about migrating on Oracle instance to AWS Aurora with PostgreSQL compatibility. For the previous one you can check here, here and here. In this post we’ll look at how you can configure change data capture so that changes on the source Oracle instance are automatically replicated to the target Aurora instance. In a real life migration this is what you probably need as long down times…
If you followed the last two posts in this little series (here and here) this is the current status of this demo migration project: We have converted the Oracle SH schema and applied it to the target AWS Aurora with PostgreSQL compatibility instance. This worked quite well but a few objects (mostly PL/SQL procedures) would need manual actions. The next and final step is to replicate the data from Oracle to the Aurora instance using…
Having the required infrastructure ready now it is time to have a look at the AWS Schema Conversion Tool (SCT). The goal of this tool is to convert a source schema (Oracle in our case) to a target schema (AWS Aurora in our case). From the description this should also migrate stored functions and procedures and we will see later on how well that works. Automatically converting Oracle’s PL/SQL to PostgreSQL’s PL/pgSQL quickly becomes tricky…
The short answer to the title of this blog post is: yes, of course you can. The more important question is: should you? The PostgreSQL documentation about tablespaces contains an explicit warning: “Placing a tablespace on a temporary file system like a RAM disk risks the reliability of the entire cluster”. This is for sure true for tablespaces containing persistent data, but what about objects/files that are created in a temporary tablespace like temporary tables…
Migrating database to the cloud is a hot topic since a few years. As more and more of our customers are in the cloud, and some of them in AWS, migrating some of their Oracle databases to AWS Aurora becomes a topic from time to time. In this little blog series we’ll have a look at how you can use the AWS Database Migration Service (DMS) and the AWS Schema Conversion Tool (SCT) for simplifying…
