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MySQL Clone Plugin Speed Test

In my previous blog, I have explained how the MySQL clone plugin works internally. In this blog, I am going to do a comparison of  Backup and Recovery speed of MySQL clone plugin with other available mysql open source backup tools.

Below tools are used for speed comparison of Backup and Recovery,

  1. Clone-Plugin
  2. Xtrabackup
  3. mysqldump
  4. mydumper with myloader
  5. mysqlpump

Test …

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Hash join in MySQL 8

For a long time, the only algorithm for executing a join in MySQL has been variations of the nested loop algorithm. With the release of MySQL 8.0.18, the server can now execute joins using hash join. This blog post will have a look at how it works, when it is used, and how it compares to the old join algorithms in MySQL in terms of performance.…

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Watch Out for Disk I/O Performance Issues when Running EXT4

Recently, at Percona Live Europe 2019, Dimitri Kravchuk from Oracle mentioned that he observed some unclear drop in performance for MySQL on an ext4 filesystem with the latest Linux kernels. I decided to check this case out on my side and found out that indeed, starting from linux kernel 4.9, there are some cases with notable (up to 2x) performance drops for ext4 filesystem in direct i/o mode.

So what’s wrong with ext4? It started in 2016 from the patch that was pushed to kernel 4.9: “ext4: Allow parallel DIO reads”. The purpose of that patch was to help to improve read scalability in direct i/o mode. However, along with improvements in pure read workloads, it also introduced regression in intense mixed random read/write scenarios. And it’s quite weird, but this issue had not been …

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Using an LSM for analytics

How do you use an LSM for analytics? I haven't thought much about it because my focus has been small data -- web-scale OLTP since 2006. It is a great question given that other RocksDB users (Yugabyte, TiDB, Rockset, CockroachDB) support analytics.

This post isn't a list of everything that is needed for an analytics engine. That has been described elsewhere. It is a description of problems that must be solved when trying to use well-known techniques with an LSM. I explain the LSM challenges for a vectorized query engine, columnar storage, analytics indexes and bitmap indexes.

There is much speculation in this post. Some of it is informed -- I used to maintain bitmap indexes at Oracle. There is also big opportunity for research and for R&D in this space. I am happy to be corrected and be told of papers that I should read.

Vectorized query engine

See …

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New Continuent Tungsten Replicator (AMI): The Advanced Replication Engine For MySQL, MariaDB, Percona Server & AWS Aurora

Discover the new Continuent Tungsten Replicator (AMI) – the most advanced & flexible replication engine for MySQL, MariaDB & Percona Server, including Amazon RDS MySQL and Amazon Aurora

We’re excited to announce the availability on the Amazon Marketplace of a new version of the Tungsten Replicator (AMI).

Tungsten Replicator (AMI) is a replication engine that provides high-performance and improved replication functionality over the native MySQL replication solution and provides the ability to apply real-time MySQL data feeds into a range of analytics and big data databases.

Tungsten Replicator (AMI)

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Database Tab Sweep

I miss a proper database related newsletter for busy people. There’s so much happening in the space, from tech, to licensing, and even usage. Anyway, quick tab sweep.

Paul Vallée (of Pythian fame) has been working on Tehama for sometime, and now he gets to do it full time as a PE firm, bought control of Pythian’s services business. Pythian has more than 350 employees, and 250 customers, and raised capital before. More at Ottawa’s Pythian spins out software platform Tehama.

Database leaks data on most of Ecuador’s citizens, including 6.7 million children – ElasticSearch.

Percona has …

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Time in Performance Schema

I've seen questions like this:
"Is there a way to know when (date and time) the last statement captured in ... was actually ran?"more than once in some discussions (and customer issues) related to Performance Schema. I've seen answers provided by my colleagues and me after some limited testing. I've also noticed statements that it may not be possible.

Indeed, examples of wall clock date and time in the output of queries from the performance_schema are rare (and usually come from tables in the information_schemasys.format_time() function converts time to a nice, human readable format, but it still remains relative - it is not a date and time when something recorded in performance_schema happened.

In this post I'd like to document the answer I've seen and …

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Testing a 99.999% Availability Distributed In-Memory Database

MySQL Cluster is an open-source distributed in-memory database. It combines linear scalability with high availability, providing in-memory real-time access with transactional consistency across partitioned and distributed datasets. It was developed to support scenarios requiring high-availability (99.999% or more) and predictable query time. Testing such a system is achieved via many interconnected pieces ranging from a large set of automated tests and manual exploratory testing. This post explores an overview of the testing methodologies we use and the current challenges we face.

Gaming, banking, telcos, and online services all are powered by fully-redundant and fault-tolerant software systems. At the heart of those systems, you can find MySQL Cluster — a distributed in-memory database having a minimum of five-9s availability (around 5 minutes a year). This open-source database provides nearly-linear …

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New dbForge Fusion tools with Visual Studio 2019 Support

dbForge Fusion is a line of Visual Studio plugins designed to simplify database development and enhance data management capabilities. This line comprises three tools: dbForge Fusion for SQL Server, dbForge Fusion for MySQL, and dbForge Fusion for Oracle. We are happy to announce new updates for each of these tools which come with many improvements […]

The post New dbForge Fusion tools with Visual Studio 2019 Support appeared first on blog.

InnoDB : Tablespace Space Management

A user defined table and its corresponding  index data, in InnoDB, is  stored in files that have an extension .ibd. There are two types of tablespaces, general (or shared) tablespace and file-per-table.  For shared  tablespaces, data from many different  tables and their corresponding indexes may reside in a single .ibd file.…

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