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Franck Pachot

DynamoDB Scan: the most efficient operation 😉

By | AWS, NoSQL | No Comments

By Franck Pachot . The title is provocative on purpose because you can read in many places that you should avoid scans, and that Scan operations are less efficient than other operations in DynamoDB. I think that there is a risk, reading those message without understanding what is behind, that people will actually avoid Scans and replace them by something that is even worse. If you want to compare the efficiency of an operation, you…

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Franck Pachot

Amazon Aurora: calling a lambda from a trigger

By | AWS, Cloud | No Comments

By Franck Pachot . You may want your RDS database to interact with other AWS services. For example, send a notification on a business or administration situation, with a “push” method rather than a “pull” one from a Cloud watch alert. You may even design this call to be triggered on database changes. And Amazon Aurora provides this possibility by running a lambda from the database through calling mysql.lambda_async() from a MySQL trigger. This is…

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Franck Pachot

Aurora Serverless v2 (preview) – CPU

By | AWS | No Comments

By Franck Pachot . This follows my previous post https://blog.dbi-services.com/aurora-serverless-v2-ram/ ‎which you should read before this one. I was looking at the auto-scaling of RAM and it is now time to look at the CPU Utilization. I have created an Aurora Serverless v2 database (please don’t forget it is the beta preview) with auto-scaling from 4 ACU to 32 ACU. I was looking at a table scan to show how the buffer pool is dynamically…

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Franck Pachot

Aurora Serverless v2 (preview) – RAM

By | AWS | No Comments

By Franck Pachot . What is Aurora Serverless? That’s the RDS Aurora name for auto-scaling: instead of provisioning an instance size (from the burstable db.t3.small with 2 vCPU and 2GB RAM to db.r5.16xlarge with 64 vCPU and 512 GB RAM) you define a range in term of ACU /Aurora Capacity Unit). ACU is about CPU + RAM. This blog post will focus on RAM. Aurora Serverless v1 In Serverless v1 the ACU goes from 1…

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Franck Pachot

Database announcements at re:Invent 2020

By | AWS | No Comments

By Franck Pachot . This year is not very nice for conferences as everything is virtual and we miss the most important: meeting and sharing with people. But the AWS re:Invent is actually a great experience. As an AWS Data Heros, I received an Oculus Quest 2 to teleport to the virtual Neon City where we can meet and have fun in Virtual Reality (but incredibly real-life chatting): A little bit of what @AWSreInvent looks…

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Franck Pachot

DynamoDB Scan (and why 128.5 RCU?)

By | AWS | No Comments

By Franck Pachot . In the previous post I described the PartiSQL SELECT for DynamoDB and mentioned that a SELECT without a WHERE clause on the partition key may result in a Scan, but the result is automatically paginated. This pagination, and the cost of a Scan, is something that may not be very clear from the documentation and I’ll show it here on the regular DynamoDB API. By not very clear, I think this…

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Franck Pachot

Cross-cloud PMM: which TCP ports to open

By | AWS, Database Administration & Monitoring | No Comments

By Franck Pachot . I recently installed Percona Monitoring & Management on AWS (free tier) and here is how to monitor an instance on another cloud (OCI), in order to show which TCP port must be opened. PMM server I installed PMM from the AWS Marketplace, following those instructions: https://www.percona.com/doc/percona-monitoring-and-management/deploy/server/ami.html. I’ll not reproduce the instructions, just some screenshots I took during the install: I have opened the HTTPS port in order to access the console,…

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Franck Pachot

DynamoDB PartiQL – part II: SELECT

By | AWS | No Comments

By Franck Pachot . In the previous post I insertd a few rows in a Demo table using the SQL-like new API on DynamoDB. I checked my items with a SELECT but was limited in the ORDER BY clause. Here is the most important to understand: there are no additional data processing engine here. PartiQL (pronounce it like ‘particle’ and it helps to avoid any kind of dyslexia) parses a statement with INSERT/UPDATE/DELETE/SELECT and calls…

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Franck Pachot

DynamoDB PartiQL – part I: INSERT

By | AWS | No Comments

By Franck Pachot . This sounds paradoxical to execute SQL statements on a NoSQL database, but we have now a new API to interact with DynamoDB, which looks like SQL. AWS data services is a collection of purpose-built database services that have their own API. The relational databases in RDS all share a similar API thanks to the SQL standard. However, for non-relational databases, there is no standard: each NoSQL databases, even if they have…

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Franck Pachot

AWS burstable EC2 and CloudWatch metrics

By | AWS | No Comments

By Franck Pachot . Your application workload is usually not constant and maybe not predictable. If you undersize the capacity, you will save money but in case of peak of activity you will have severe performance issues. Thus, you need to size the capacity for peak workloads: you pay for idle CPU when out of those peaks. This is one major reason for virtualization and cloud: elasticity. Because the hardware is shared by multiple applications,…

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