Infrastructure at your Service
By Franck Pachot . You can create a VM with SQL Server running in the Oracle Cloud. This is easy with a few clicks on the marketplace: Here are the steps I did above: Oracle Cloud -> Marketplace -> Application -> Category -> Database management You have multiple flavors. I’ve chosen the lastest cheaper “Microsoft SQL 2016 Standard with Windows Server 2016 Standard” Select the compartment and “Launch Instance” Choose a name, and the network…
By Franck Pachot . Since Aug. 4, 2020 we have the possibility to rename an Autonomous Database (ATP, ADW or AJD – the latest JSON database) on shared Exadata infrastructure (what was called ‘serverless’ last year which is a PDB in a public CDB). As the PDB name is internal, we reference the ADB with its database name is actually a part of the service name. I have an ATP database that I’ve created in…
By Franck Pachot . That’s common to any data structure, whether it is RDBMS or NoSQL, indexes are good to accelerate reads but slow the writes. This post explains the consequences of adding indexes in DynamoDB. Secondary Indexes What we call an index in DynamoDB is different from an index in RDBMS. They have the same goal: store your data with some redundancy in order to have it physically partitioned, sorted, and clustered differently than…
By Franck Pachot . DynamoDB is a cloud-native, managed, key-value proprietary database designed by AWS to handle massive throughput for large volume and high concurrency with a simple API. simple API: Get, Put, Query, Scan on a table without joins, optimizer, transparent indexes,… high concurrency: queries are directed to one shard with a hash function massive throughput: you can just add partitions to increase the IOPS large volume: it is a shared-nothing architecture where all…
By Franck Pachot . In The myth of NoSQL (vs. RDBMS) “joins dont scale” I explained that joins actually scale very well with an O(logN) on the input tables size, thanks to B*Tree index access, and can even be bounded by hash partitioning with local index, like in DynamoDB single-table design. Jonathan Lewis added a comment that, given the name of the tables (USERS and ORDERS). we should expect an increasing number of rows returned…
By Franck Pachot . I have written a few blog posts about some NoSQL (vs. RDBMS) myths (“joins dont scale”, “agility: adding attributes” and “simpler API to bound resources”). And I’ll continue on other points that are claimed by some NoSQL vendors and are, in my opinion, misleading by lack of knowledge and facts about RDBMS databases. But here I’m sharing an opposite opinion: SQL being user-friendly is now a myth. Yes, that was the…
By Franck Pachot . NoSQL provides an API that is much simpler than SQL. And one advantage of it is that users cannot exceed a defined amount of resources in one call. You can read this in Alex DeBrie article https://www.alexdebrie.com/posts/dynamodb-no-bad-queries/#relational-queries-are-unbounded which I take as a base for some of my “Myth of NoSQL vs RDBMS” posts because he explains very well how SQL and NoSQL are perceived by the users. But this idea of…
By Franck Pachot . Announced by Larry Ellison last week, here it is: the Autonomous Data Guard. You can try it, unfortunately not on the Free Tier. First you create an Autonomous Database (ATP or ADW) and then you enable Autonomous Data Guard. You know that “Autonomous” is the marketing brand for the services that automate a lot of things, sometimes based on features that are in Oracle Database for a long time. So let’s…
By Franck Pachot . J’essaie quelque chose de nouveau. Je publie beaucoup en anglais (blog, articles, présentations) mais cette fois quelque chose de 100% francophone. En sortant du confinement, on reprend les transports (train, voiture,…) et c’est l’occasion de se détendre en musique mais aussi de s’informer avec des podcasts. J’ai l’impression que c’est un format qui a de l’avenir: moins contraignant que regarder une video ou ou lire un article ou une newsletter. Alors…
By Franck Pachot . The FETCH FIRST … ROWS ONLY syntax arrived in Oracle 12c and is much more convenient than using a subquery with ‘ORDER BY’ wrapped in a “WHERE ROWNUM < …” around it. But as I mentioned in a previous post it required the FIRST_ROWS() hint to get correct estimations. In SQL you don’t want to overload your code for performance, right? The RDBMS optimizer does the job for you. This was…
