Tag: row

Feed: Planet MySQL; Author: MySQL High Availability; In part 1, we took a brief, high-level look at the various protocols and mechanisms used to keep the Data Dictionary (DD) of MySQL servers connected to a MySQL Cluster in synchronization with each other and with the NDB Dictionary. More specifically, we explored the problems with the implementation of user-triggered synchronization in the NDB Cluster 7.x versions. These concerns are addressed in NDB Cluster 8.0 through a new feature: Automatic Schema Synchronization (or auto schema sync for short). A new component called Metadata Change Monitor has been introduced to detect any NDB ... Read More

Feed: Planet MySQL; Author: MyDBOPS; As a part of Mydbops Consulting we have a below problem statement from one of our client. “We have a high powered server for reporting which in turn powers our internal dashboard for viewing the logistics status.Even with a high end hardware, we had a heavy CPU usage and which in turn triggers spikes in replication lag and slowness. Below is the hardware configuration.“ OS : Debian 9 (Stretch) CPU : 40 RAM : 220G (Usable) Disk : 3T SSD with 80K sustained IOPS. MySQL : 5.6.43-84.3-log Percona Server (GPL) Datasize : 2.2TB Below is ... Read More

Feed: MemSQL Blog. Author: Rick Negrin. There is a trend in industry which says that modern applications need to be built on top of one or more special-purpose databases. That every application benefits from using the best-of-breed technology for each requirement. And that the plethora of special-purpose options available from certain cloud providers is reasonable to manage. That’s all BUNK. The reality is that navigating the choices, figuring out how to use them effectively, and dealing with the ETL and inevitable data sprawl, is so difficult that the pain far outweighs any technical advantage you might get. In the vast ... Read More

Feed: Planet MySQL; Author: Severalnines; April 2018 is not just a date for the MySQL world. MySQL 8.0 was released there, and more than 1 year after, it’s probably time to consider migrating to this new version. MySQL 8.0 has important performance and security improvements, and, as in all migration to a new database version, there are several things to take into account before going into production to avoid hard issues like data loss, excessive downtime, or even a rollback during the migration task. In this blog, we’ll mention some of the new MySQL 8.0 features, some deprecated stuff, and ... Read More

Feed: What's New. Author: Joshua Milligan. All of the Nest thermostat data I capture via the script is in a Google Sheet and I can directly connect to it with Tableau Prep (versions 2019.4 and newer)! The Tableau Flow itself looks a bit complex, but it’s mostly just the same steps duplicated for each measure: Each piece, like Inside Temps is primarily splitting the really, really long string: then pivoting so that all those measurements and times are together in a single column: And then doing some additional splitting out of the measure from the timestamp, parsing the date and ... Read More

Feed: AWS Big Data Blog. Many AWS customers use a multi-account strategy. A centralized AWS Glue Data Catalog is important to minimize the amount of administration related to sharing metadata across different accounts. This post introduces capability that allows Amazon Athena to query a centralized Data Catalog across different AWS accounts.Overview of solution In late 2019, AWS introduced the ability to Connect Amazon Athena to your Apache Hive Metastore. Using this functionality, you can also configure Athena to point to a Data Catalog in a different account. The Hive Metastore functionality uses an AWS Lambda function to federate queries to ... Read More

Feed: Planet MySQL; Author: MySQL Performance Blog; If you’re using MySQL’s Performance Schema you may use “query digests” as IDs to identify specific query patterns in the events_statements_summary_by_digest Performance Schema Table.You might assume these hashes are stable between different versions, so, for example, when upgrading from MySQL 5.7 to MySQL 8, you can compare the query response time and other execution details for the same hashes as part of your upgrade process and have confidence that queries run the same (or better) after the upgrade.   Unfortunately, you can’t.For some reason, the hashing algorithm is different between MySQL 5.6,  MySQL ... Read More

Feed: Planet MySQL; Author: Severalnines; With MySQL 8.0 Oracle adopted a new approach to development. Instead of pushing features with major versions, almost every minor MySQL 8.0 version comes with new features or improvements. One of these new features is what we would like to focus on in this blog post.  Historically MySQL did not come with good tools for provisioning. Sure, you had mysqldump, but it is just a logical backup tool, not really suitable for larger environments. MySQL enterprise users could benefit from MySQL Enterprise Backup while community users could use xtrabackup. Neither of those came with a ... Read More

Feed: The Information Lab. Author: Chris Love. 19 January, 2020 Creating UpSet Plots in Tableau Authored by Chris Love. Feel free to chat on Twitter @chrisluv. Looking through #MakeoverMonday I noticed a couple of Venn Diagrams this week. Venn diagrams are very popular, and audiences will be familiar with them, but are difficult to build in Tableau. What is more there are some great alternatives – especially when trying to build plots with more than 3 combination states. UpSet Plots UpSet plots are a great alternative to a Venn. While they may require some explaining to an audience they can ... Read More

Feed: Planet MySQL; Author: Valeriy Kravchuk; I'd like to continue reviewing MySQL bug reports from Community users that I considered interesting and subscribed to. Unlike in the previous post in this series, I am not going to check test cases on any competitor product, but will use only recently released MySQL 5.7.29 and 8.0.19 for checks, if any. This time I'll concentrate on bugs reported in November 2019.As usual, I mostly care about optimizer, InnoDB and replication related bugs. Here is the list:Bug #97476 - "Range optimizer skips rows". This bug reported by Ilya Raudsepp looks like a clear regression in ... Read More