Thinking about upgrading your MySQL database? When performing an upgrade, there are some factors you need to consider and some best practices that can be followed to help ensure the process goes as smoothly as possible.
I’d like to share with everyone how awesome CoreOS is for leveraging Docker. We use this set up for our search proxy here at Swig (a community for drink enthusiasts for iOS and Android). Neo4j is used as our database and as stated in my previous blog post, it works brilliantly as a startup-friendly (read: flexible) database.
Percona Toolkit’s pt-table-checksum is a great tool to find data inconsistencies between a MySQL master and its replicas. However, you may want to know which exact rows are different to identify the statements that created the inconsistency.
When writing DDL in SQL, you can specify a couple of constraints on columns, like NOT NULL or DEFAULT constraints. Some people might wonder, if the two constraints are actually redundant, i.e. is it still necessary to specify a NOT NULL constraint, if there is already a DEFAULT clause?
This post is an informal journal of my trip through the guts of Postgres. I’ll describe the path I took and what I saw along the way. I’ll use a series of simple, conceptual diagrams to explain how Postgres executed my query.
The 2014 edition of Percona Live London brought together attendees from 30 countries to hear insightful talks from leaders in the MySQL community. The conference kicked off on Monday with a full day of tutorials followed by the very popular Community Dinner featuring a double decker bus shuttle from the conference to the event.
Submit your speaking proposals now for tutorials or breakout session on the Percona Live conference website. Accepted speakers receive a full conference pass and the sincere gratitude of attendees who will eagerly await your presentations.
A deadlock in MySQL happens when two or more transactions mutually hold and request for locks, creating a cycle of dependencies. In a transaction system, deadlocks are a fact of life and not completely avoidable.
Optimistic locking discards all incoming changes that are relative to an older entity version. But everything has a cost and optimistic locking makes no difference.
PL/SQL is one of those things. Most people try to stay clear of it. Few people really love it. I just happen to suffer from stockholm syndrome, since I’m working a lot with banks.
Make sure you didn't miss anything with this list of the Best of the Week in the SQL Zone (October 31 - November 07). Including Hibernate Collections Optimistic Locking, MySQL full text search Q&A, and an interview with Facebook MySQL DB engineers.
MySQL database usage is popular in OpenStack. Core OpenStack services for Compute (Nova), Storage (Cinder), Neutron (Networking), Image (Glance) and Identity (Keystone) all use MySQL database.
There's more than one way to 'split' a table.
Continuing our journey here we see some others operators exist in our execution plan. Here is the query and Execution Plan that we are working from couple of weeks.
This post is going to be about language processing. Language processing could be anything like an arithmetic expression evaluator, a SQL parser or even a compiler or interpreter. Many times when we build user facing products, we give users a new language to interact with the product.
Continuing my previous article Understanding Execution Plan [ When Table JOIN occurs Part – I ], here we are describing the other process of Execution Plan.
Hibernate provides an optimistic locking mechanism to prevent lost updates even for long-conversations.
I spoke with Facebook database engineers Yoshinori “Yoshi” Matsunobu and Shlomo Priymak about their upcoming sessions along with what’s new at Facebook since our last conversation back in April.
In my previous article we are just using a single table as per our example is concern, Now in this article we are going to see the different table join each other’s and make a single data set by using JOIN.
Make sure you didn't miss anything with this list of the Best of the Week in the SQL Zone (October 24 - October 31). Here they are, in order of popularity.
Yesterday (Oct. 22) I gave a presentation titled “MySQL 5.6 Full Text Search Throwdown.” If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to folks who asked the great questions. I answered as many as we had time for during the session, but here are all the questions with my complete answers
Helpful, step-by-step instructions for setting up PHP and MySQL on OS X Yosemite.
In many write-intensive workloads Innodb/XtraDB storage engines you may see hidden and dangerous “debt” being accumulated – unpurged transaction “history” which if not kept in check over time will cause serve performance regression or will take all free space and cause an outage. Let’s talk about where it comes from and what can you do to avoid running into the trouble.
I have just watched an interesting conversation between Martin Fowler and Badri Janakiraman about #hexagonalrails, and in particular about the role of databases. The central question in the discussion is whether the database should be considered outside or inside the domain.
A Hibernate persistence context can hold one and only one reference of a given entity. The first level cache guarantees session-level repeatable reads.