Introduction As I explained in this article, multitenancy is an architectural pattern which allows you to isolate customers even if they are using the same hardware or software components. There are multiple ways you can achieve multitenancy, and in this article, we are going to see how you can implement a multitenancy architecture using the … Continue reading Hibernate database catalog multitenancy →
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Introduction In software terminology, multitenancy is an architectural pattern which allows you to isolate customers even if they are using the same hardware or software components. Multitenancy has become even more attractive with the widespread adoption of cloud computing. A relational database system provides a hierarchy structure of objects which, typically, looks like this: catalog … Continue reading A beginner’s guide to database multitenancy →
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Windowing functions are a critical tool for grouping rows of data
that are related to other rows. But they go far beyond the
regular aggregate functions found in MySQL 5.7 and earlier. In
MySQL 8 you do not have to collapse all the information down into
a single output row. Each row can retain its individual identity
but the server can analyze the data as a unit.
Statistics and Damned Lies Finding the total Population of
the District Texas from the world.city table
is simple.
SQL> select District, sum(Population)
from city where district = 'Texas';
+----------+-----------------+
| District | sum(Population) |
+----------+-----------------+
| Texas
| 9208281 |
+----------+-----------------+
1 row in set (0.0068 sec)
…
There was an interesting but hard to read post on StackOverflow about how 'insert select delete'
data from a MySQL JSON data type column. The first line of
the writer's problem is a little confusing '
In order to record user mac_address and count mac_address to
restrict user login's pc or notebook to control user available
max for example (it's work)' but the examples reveled more
about what was desired. The idea was to track MAC address used by
various users and the author of the question was wondering how to
up data a JSON Array of values with JSON_INSERT. INSERT is
for inserting and the better choice would be JSON_ARRAY_APPEND or
JSON_ARRAY_INSERT. But what caught my eye was the
second question: Select sql command for json column ? could be …
“We made it a point to hire really smart, visionary
people and then let them do their work.
I wanted to delegate and let people be in charge of things. My
own decision-making process was to decide who got to decide. To
make decisions, you have to first outline the problem, and if you
hire really great people, they’re going to know more about the
problem they’re dealing with than you ever will.”–Scott
McNealy
I have interviewed Scott McNealy. Scott is a Silicon Valley pioneer, most famous for co-founding Sun Microsystems in 1982. We talked about Innovation, AI, Big Data, Redis, Curriki and Wayin.
RVZ
Q1. You co-Founded Sun Microsystems in 1982, and served as CEO and Chairman of the Board for 22 years. What are the main lessons learned in all these years?
Scott …
[Read more]
The MySQL Document Store is a NoSQL JSON document store built
upon well known MySQL database technology. PHP runs about
eight percent of the Internet. So putting the two together
is a big priority for me. So this blog post is about getting all
this together on a Ubuntu 18.04 system.
Note that I will be teaching PHP and the X DevAPI at Oracle Code
One and hopefully in some tutorials/workshops this year.
These session will feature the X DevAPI installed on Virtual Box
images and I probably will not have time to cover these steps in
detail but I will point to this as reference material.
PHP 7.2 PHP's performance has really skyrocketed with the
seven series and the newer betas are looking very
impressive. But to use the new X Devapi you will need to
get the shared object for it into your PHP server.
The MySQL X DevAPI PECL Extension
…
This year the Zero to DBA Hero track at the Southeas
Llinuxfest expands to a second day. The event is
free to attend but it helps if you pre register. Here is
the agenda of that you will see in Charlotte June 8th, 9th, and
10th.
MySQL Talks at SELF – Zero to
DBA Hero Track Linode Ballroom
Friday
9am 20 years of MySQL, 20 years of
PHP, and 10 Years of SELF -- What the heck has been going on?
Dave Stokes
10:15 Introducing the MySQL Document Store
Charles Bell, PhD
11:30 Performance Analysis and Troubleshooting Methodologies
for Databases Peter Zaitsev
1:30 MySQL Without the SQL -- Oh My! Dave Stokes
4:00 Introducing MySQL InnoDB Cluster Charles Bell,
PhD
Saturday
9am …
When maintainng any piece of software, we usually deal with two kind of actions:
bugs and features
A bug happens when there is an error in the software, which does not behave according to the documentation or the specifications. In short, it's a breech of contract between the software maintainer and the users. The promise, i.e. the software API that was published at every major version, is broken, and the software must be reconciled with the expectations and fixed, so that it behaves again as the documentation says. When we fix a bug in this way, we increment the revision number of the software version …
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Pretend you have a JSON array of data that looks roughly like the
following.
mysql> insert into x(y) values('["a","b","c","d"]');
Query OK, 1 row affected (0.10 sec)
You could get all the values from that array using
$[*]
mysql> select y->"$[*]" from x;
+----------------------+
| y->"$[*]" |
+----------------------+
| ["a", "b", "c", "d"] |
+----------------------+
1 row in set (0.00 sec)
Or the individual members of the array with an index that starts
with zero.
mysql> select y->"$[0]" from x;
+-----------+
| y->"$[0]" |
+-----------+
| "a" |
+-----------+
1 row in set (0.00 sec)
But what about the times you want the last item in the array and
really do not want to loop through all the items? How about using …
MySQL 8.0 GA is right around the corner. I
don't have precise information about its release, as I don't work
at Oracle. If I did, I would probably know, but I couldn't tell
when the release is scheduled to appear because of company
policies. I can, however, speculate and infer, based of my
experience with previous releases. My personal assessment is that
the release will appear before 9:00am PT on April 24, 2018. The "before"
can be anything from a few minutes to one week in advance.
Then, again, it may not happen at all if someone finds an
atrocious bug that needs to be fixed asap.
Either way, users are keen on testing the new release in its current state of release candidate. Here I show a few methods that allow you to have a taste of the new …
[Read more]