Authors: Sunny Bains, Jiamin Huang (University of Michigan)
What is Transaction Scheduling?
Locking is one of the most popular mechanisms for concurrency control in most database systems, including Oracle MySQL. One major question, however, seems to have been overlooked by all database vendors:
Q: When multiple transactions are waiting for a lock on the same object, which one(s) should get the lock first?…
There’s a GTID_SUBTRACT function, and the manual shows how to write your own cheap GTID_UNION, but not a GTID_INTERSECT. Fortunately it’s easy to write your own, as it’s just subtracting twice.
CREATE FUNCTION GTID_INTERSECT(g1 TEXT, g2 TEXT)
RETURNS TEXT DETERMINISTIC
RETURN GTID_SUBTRACT(g1, GTID_SUBTRACT(g1, g2));
What use is it?
SET @slave_executed =
'33738f8c-c1a5-11e7-8fc3-0a002700000f:1-681577,
421d139e-04b9-11e7-b702-0050569935dc:1-13764443,
52b9a949-d79d-11e3-80dd-0050568d193e:1-1207378:1207380-1261803:1261805-1267098:1267100-1267416:1267418-1589733';
SET @master_executed =
'33738f8c-c1a5-11e7-8fc3-0a002700000f:1-730294,
421d139e-04b9-11e7-b702-0050569935dc:1-13764443,
52b9a949-d79d-11e3-80dd-0050568d193e:1-1207378:1207380-1261803:1261805-1589733';
SET @master_purged =
'33738f8c-c1a5-11e7-8fc3-0a002700000f:1-681582,
…
Today I am going to share with you how to create insert update delete operation with validation in codeigniter 3 application with demo examplethis tutorial will help to create simple CRUD Create Read Update Delete Operation application using MySQL Database with validation As we know well we al
Today I am going to share with you how to create insert update delete operation with validation in codeigniter 3 application with demo examplethis tutorial will help to create simple CRUD Create Read Update Delete Operation application using MySQL Database with validation As we know well we al
MySQL Change default directories
While reading this heading everybody things like, yeah its pretty old topic, we can get many articles by googling. But you know what sometimes well known things never work for us. This time it happened for me, my bad. I have done this many times. But most of us changed the default Data Directory only. Only a few of us thinking about change MySQL default data,binlog, error log directories.
I can easily change the Data directory, But while enabling binlog, and error log I got an error.
mysqld: File '/mysql/binlog/mysql-bin.index' not found (Errcode: 13)
So this is the reason for wrote this blog.
My Server Setup:
OS: Ubuntu 14.04LTS 64Bit
MySQL: 5.5.58
Destination Directories:
Data: /mysql/data
Binlog: /mysql/data
…
[Read more]
There are a few MySQL or mixed MySQL/other-DBs jobs in the UK if
you are looking to get into the industry or move up:
In the 1990s C.J.Date said: "The rule by which it is determined within the standard that one key word needs to be reserved while another need not be is not clear to this writer."
Nothing has changed since then, except there are more reserved words. No DBMS uses the standard list. So I think that it is probably best to know what words are reserved in product X that are not reserved in product Y. If you know, you can avoid syntax errors when you update or migrate.
I'll present several comparisons, ending with a grand chart of all the reserved words in the standard and six current DBMSs.
First here's a screenshot of ocelotgui where I'm hovering over
the word BEGIN.
What I'm illustrating is that you can't depend on intuition and
assume BEGIN is reserved, but a GUI client can tell you from
context: it's a …
Join Percona Chief Evangelist Colin Charles as he covers happenings, gives pointers and provides musings on the open source database community.
This week we saw the closing of the CFPs for MariaDB’s user conference, M18. Peter Zaitsev and I submitted for Percona (don’t forget that there is also a developer’s conference tacked on to this event). We don’t have high expectations of getting a talk there, but hey – you never know! I submitted a talk on running MariaDB in the cloud (either hosted on Amazon RDS or Rackspace) or in your own compute instance. Another talk on capacity planning seemed to make sense as well. …
[Read more]Percona announces the release of Percona Monitoring and Management 1.4.1 on Thursday, November 2nd, 2017. This release contains fixes to bugs found after Percona Monitoring and Management 1.4.0 was released. It also introduces two important improvements. We replaced the btrfs file system with XFS in AMI and OVF images, and the Prometheus dashboard has been enhanced to offer more information.
For install and upgrade instructions, see Deploying Percona Monitoring and Management.
Improvements
PMM-1567: The …
Notes/errata/updates for Chapter 9:
See the official book errata at http://tahaghoghi.com/LearningMySQL/errata.php –
Chapter 9 includes pages 297 – 350.
In the fourth paragraph of this chapter, starting with “Most applications don’t need superuser privileges for day-to-day activities” they give you some reasons why you want to create users without the SUPER privilege. There are better reasons than the book gives, which are at the MySQL Manual page for the SUPER privilege.
In the section “Creating and Using New Users” (p. 300) they say “There’s no limit on password length, but we recommend using eight or fewer characters because this avoids problems with system libraries on some platforms.” You should ignore this, this book …
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