This post is a sister post to MySQL Master Replication Crash Safety Part #4: benchmarks of high and low durability. There are no introduction or conclusion to this post, only landing sections: reading this post without its context is not recommended. You should start with the main post and come back here for more details.
Environment
My benchmark environment is composed of three vms in
Next in our Benefits of SQL Diagnostic Manager for MySQL (formerly Monyog) blog series, we discuss monitoring and understanding performance trends using visual analytics and the display dashboard of SQL Diagnostic Manager for MySQL. If you missed it, you can read last week’s blog on identifying and analyzing problematic SQL queries.
View and Understand Trends By Analyzing Historical Data
Configure the time duration for storing the data collected by SQL Diagnostic Manager for MySQL. It stores the data in a high-performance database (that is, the embedded relational database management system SQLite). By analyzing historical data, quickly obtain answers to questions like:
Fairly recently, we’ve upgraded to MySQL 8; it’s been a relatively smooth transition, however, some minor differences needed to be handled. One of them is the behavior of trailing spaces.
Trailing spaces are a (not in a good way) surprising, but also widely covered argument. This article gives a short overview, and relates it to how this affects people upgrading to MySQL 8.0.
Contents:
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I have a presentation next month on MySQL and GIS. MySQL
8.0 has benefited greatly from the three dimensional libraries
from Boost.Geometry. There are many facets to the Geographic Data
world that it is damn near impossible not to lurch down one
rabbit hole into another in an unending spiral of acronyms,
standards, projections, and functions. But thankfully I
have MySQL Workbench to aid me.
Texas
I wanted some test data to use for some GIS exercises and was
very happy to find many useful sets curated by the OpenStreetMaps
folks. Shapefiles are used to hold the various data points of an
item of interest. I had assumed that the data would have
some sort of longitude/latitude pairs but was wondering what I
would need to do to work with that data and what ever came
bundled with it. I download the Texas data and then …
Are you looking to get started with the world’s most popular open-source database, and wondering how you should setup your MySQL hosting? So many default to Amazon RDS, when MySQL performs exceptionally well on Azure Cloud. While Microsoft Azure does offer a managed solution, Azure Database, the solution has some major limitations you should know about before migrating your MySQL deployments. In this post, we outline the best way to host MySQL on Azure, including managed solutions, instance types, high availability replication, backup, and disk types to use to optimize your cloud database performance.
MySQL DBaaS vs. Self-Managed MySQL
The first thing to consider when weighing between self-management and a MySQL Database-as-a-Service …
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Note: I am no longer working for Oracle/MySQL. This post is
based on public information.
The MySQL 8.0.17 release is around the corner. Let's take a look
at the new features in the upcoming release.
InnoDB redo log archive
InnoDB added new parameter
“--innodb-redo-log-archive-dirs” in 8.0.17, according to
the doc page. The implementation of both page archive and redo
log archive has been in the code for a while, under arch
directory. This feature can be used by backup and database
clone.
Multi-Valued Indexes
As of MySQL 8.0.17, InnoDB supports multi-valued indexes. A multi-valued index is a secondary index defined on a column that stores an array of values. A “normal” index has one index record for each data record (1:1). A multi-valued index …
[Read more]During our work in support, we see this again and again: “I try to connect to MySQL and am getting a 1045 error”, and most times it comes accompanied with “…but I am sure my user and password are OK”. So we decided it was worth showing other reasons this error may occur.
MySQL 1045 error Access Denied triggers in the following cases: 1) Connecting to wrong host:
[engineer@percona]# mysql -u root -psekret mysql: [Warning] Using a password on the command line interface can be insecure. ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
If not specifying the host to connect (with -h flag), MySQL client will try to connect to the localhost instance while you may be trying to connect to another host/port instance.
Fix: Double check if you are trying to connect to localhost, or be sure to specify host and port if it’s not localhost:
…[Read more]
SQL Except Clause Example | Except Statement In SQL is today’s topic. The SQL EXCEPT operator is used to combine two select statements, which in turn returns the row that is present in the first select statement and not in the second select statement. This Clause acts like a subtract operation that we perform in sets and Venn diagrams.
SQL Except Clause Example
In SQL, EXCEPT returns those tuples that are returned by the first SELECT operation, and not returned by the second SELECT operation.
#Pictorial Representation
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The Question Recently, a customer asked us:
After importing a new section of user data into our Tungsten
cluster, we are seeing perpetually rising replication lag. We are
sitting at 8.5hrs estimated convergence time after importing
around 50 million rows and this lag is climbing continuously. We
are currently migrating some of our users from a NoSQL database
into our Tungsten cluster. We have a procedure to write out a
bunch of CSV files after translating our old data into columns
and then we recursively send them to the write master using the
mysql client. Specifically our import SQL is doing LOAD
DATA LOCAL INFILE and the reading in a large CSV file to
do the import. We have 20k records per CSV file and we have 12
workers which insert them in parallel.
Simple Overview The Skinny
In cases like this, the slaves are having trouble with the database unable to keep up with the apply stage …
[Read more]Last year, we asked you a few questions in a blog poll and we received a great amount of feedback. This year, we wanted to follow up on those same survey questions to see what may have changed over the last 12 months. So with that in mind, we’re hoping you can take a minute or so to answer the first survey question in this series: What Keeps You Up At Night? Is it fixing emergencies? Bad queries? Cost concerns? Inquiring minds want to know!
Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.
This poll question will be up for one month and will be maintained over in the sidebar should you wish to come back at a later date and take part. We look forward to seeing your responses!