MySQL theoretical limits are known and they can be found in the manual, they include:
MyISAM permits data and index files to grow up to 256 TiB by default, but this limit can be changed up to the maximum permissible size of 65,536 TiB (256^7 − 1 bytes). The maximum tablespace size depends on the InnoDB page size: 64 TiB for 16 KiB pages.(The maximum tablespace size is also the maximum size for a
Queries with LIMITs and OFFSETs are common in application that
require pagination and in some cases might work well for a
while.
In many cases though, they become slow and painful once the
OFFSET has a high value.
Why OFFSET is so slow?
Well, in most cases, low offset queries are not slow. The problem
starts with high OFFSET values.
If your query is using the following limit clause: “LIMIT 50000,
20”, it’s actually requesting the database to go through 50,020
rows and throw away the first 50,000. This action can have a high
cost an impact response time.
You may ask yourself “who the heck is going to skip to page
50,000 in my application?”.
Let’s list few possible use cases:
Dear MySQL Users,
MySQL Connector/J 5.1.43, a maintenance release of the production 5.1 branch has been released. Connector/J is the Type-IV pure-Java JDBC driver for MySQL.
MySQL Connector Java is available in source and binary form from
the Connector/J download pages at
http://dev.mysql.com/downloads/connector/j/5.1.html and mirror
sit
repositories.
MySQL Connector Java (Commercial) is already available for
download on the My Oracle Support (MOS) website. This release
will be available on eDelivery
(OSDC) in next month’s upload cycle.
As always, we recommend that you check the “CHANGES” file in the download archive to be aware of changes in behavior that might affect your application.
MySQL Connector/J 5.1.43 includes the following general bug fixes
and improvements, also available in more detail on
http://dev.mysql.com/doc/relnotes/connector-j/en
nges in MySQL Connector/J …
This Log Buffer Edition covers Oracle, SQL Server and MySQL.
Oracle:
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Today Oracle released a very large „monster“ Upgrade. This July 2017 Update includes the first time the new RU „Release …
[Read more]This Log Buffer Edition covers Oracle, SQL Server and MySQL.
Oracle:
Protecting Financial Data with Oracle WebCenter and Adobe LiveCycle
Oracle Forms 12c oracle.security.jps.JpsException Error after Database change
The Future of Content Management: Oracle Content & Experience Cloud
Today Oracle released a very large „monster“ Upgrade. This July 2017 Update includes the first time the new RU „Release …
[Read more]In this blog, we’ll look at how improvements to Percona XtraDB Cluster improved IST performance.
Introduction
Starting in version 5.7.17-29.20 of Percona XtraDB Cluster significantly improved performance. Depending on the workload, the increase in throughput is in the range of 3-10x. (More details here). These optimization fixes also helped improve IST (Incremental State Transfer) performance. This blog is aimed at studying the IST impact.
IST
IST stands for incremental state transfer. When a node of the cluster leaves the cluster for a short period of time and then rejoins the cluster it needs to catch-up with cluster state. As part of this sync …
[Read more]via GIPHY Amazon releases a new database offering every other day. It sure isn’t easy to keep up. Join 35,000 others and follow Sean Hull on twitter @hullsean. Let’s say you’re hiring a devops & you want to suss out their database knowledge? Or you’re hiring a professional services firm or freelance consultant. Whatever the … Continue reading How to interview an amazon database expert →
In this post, we’ll use a blog poll to find out what operating system you use to run your development database servers.
In our last blog poll, we looked at what OS you use for your production database. Now we would like to see what you use for your development database.
As databases grow to meet more challenges and expanding application demands, they must try and get the maximum amount of performance out of available resources. How they work with an operating system can affect many variables, and help or hinder performance. The operating system you use for your database can impact consumable choices (such as hardware and memory). The operating system you use can also impact your choice of database engine as well (or vice versa).
When new projects, new applications or services or testing new architecture …
[Read more]In this blog post, I’ll talk about multi-threaded slave statistics printed in MySQL error log file.
MySQL version 5.6 and later allows you to execute replicated events using parallel threads. This feature is called Multi-Threaded Slave (MTS), and to enable it you need to modify the
slave_parallel_workers
variable to a value greater than 1.
Recently, a few customers asked about the meaning of some new statistics printed in their error log files when they enable MTS. These error messages look similar to the example stated below:
[Note] Multi-threaded slave statistics for channel '': seconds elapsed = 123; events assigned = 57345; worker queues filled over overrun level = 0; waited due a Worker queue full = 0; waited due the total size = 0; waited at clock conflicts = 0 waited (count) …[Read more]
Group Replication has been around for some time now and the feedback from community is overwhelming. One of the suggestions (BUG#84795) received is related to deploying a mechanism to prevent a server from being updated after stopping group replication.…
