This is a blog post about an issue that can occur during a database upgrade and produces a misleading error message. If you’re already aware of it, the workaround is trivial. However, when it happened to me during the testing…
Read More >This post is about a Statspack anomaly I discovered while analyzing execution trends of a particular SQL on one of our clients’ databases. I decided to share it, since its appearance can be misleading. The database in question was an…
Read More >This is the fourth in a series of blog posts that covers the details to deploy a high available set up of Oracle Enterprise Manager 13.5 using Oracle Cloud Infrastructure’s resources. Recap This is the fourth of a six-part…
Read More >Here at Pythian, we love our data. Our code is no exception (pun sort of intended), so I’ll be covering dataclasses in Python today. The problem As a Python developer, you’ve almost certainly run into code that looks like the…
Read More >Got too many tombstones? This blog post will talk about how to deal with tombstones once you already have them. For more information about tombstones, check out this post: Examining the Lifecycle of Tombstones in Apache Cassandra. Verifying the presence…
Read More >Apache Beam is an SDK (software development kit) available for Java, Python, and Go that allows for a streamlined ETL programming experience for both batch and streaming jobs. It’s the SDK that GCP Dataflow jobs use and it comes with…
Read More >This blog post is based on a real customer case, and illustrates how v$sql reports execution statistics for certain DML types of operations (I purposely have not named which DML types … yet). These reports can be misleading when troubleshooting…
Read More >In this post I’ll describe a problem which occurs when creating and using a database service name which starts with the pluggable database’s (PDB) name, and has a dot (“.”) after it: “<pdb_name>.<optional_suffix>.” I noticed this issue when I was…
Read More >In this post, I’ll present the statspack_top_sqls.sql script, which returns SQL performance statistics by mining the Statspack repository. In a previous blog post, I presented the statspack_load_trends.sql and the AWR_load_trends.sql scripts, which provide a high-level overview of workload dynamics on…
Read More >There are various ways that we can approach the analysis of a past database performance problem. The initial steps usually differ based on their scope. Is it limited to a certain SQL/process/task, or is it perceived as a database-wide slowdown?…
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