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Displaying posts with tag: Oracle (reset)
External Tables + Merge

This is an example of how you would upload data from a flat file, or Comma Separated Value (CSV) file. It’s important to note that in the file upload you are transferring information that doesn’t have surrogate key values by leveraing joins inside a MERGE statement.

Step #1 : Create a virtual directory

You can create a virtual directory without a physical directory but it won’t work when you try to access it. Therefore, you should create the physical directory first. Assuming you’ve created a /u01/app/oracle/upload file directory on the Windows platform, you can then create a virtual directory and grant permissions to the student user as the SYS privileged user.

The syntax for these steps is:

CREATE DIRECTORY upload AS '/u01/app/oracle/upload';

Step #2 : Position your CSV file in the physical …

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On RDBMS, NoSQL and NewSQL databases. Interview with John Ryan

“The single most important lesson I’ve learned is to keep it simple. I find designers sometimes deliver over-complex, generic solutions that could (in theory) do anything, but in reality are remarkably difficult to operate, and often misunderstood.”–John Ryan

I have interviewed John Ryan, Data Warehouse Solution Architect (Director) at UBS.


Q1. You are an experienced Data Warehouse architect, designer and developer. What are the main lessons you have learned in your career?

John Ryan: The single most important lesson I’ve learned is to keep it simple. I find designers sometimes deliver over-complex, generic solutions that could (in theory) do anything, but in reality are remarkably difficult to operate, and often misunderstood. I believe this stems from a lack of understanding of the …

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JDBC Driver Connection URL strings

Introduction Ever wanted to connect to a relational database using Java and didn’t know the URL connection string? Then, this article is surely going to help you from now on. Oracle The JDBC connection properties look as follows: JDBC Driver oracle.jdbc.OracleDriver JDBC Url jdbc:oracle:thin:@localhost:1521/orclpdb1 Hibernate Dialect org.hibernate.dialect.Oracle12cDialect And, if you want to connect using a … Continue reading JDBC Driver Connection URL strings →

The post JDBC Driver Connection URL strings appeared first on Vlad Mihalcea.

How caching_sha2_password leaks passwords

Oracle recently announced a new authentication plugin: caching_sha2_password. This was added in 8.0.4, the second release candidate for MySQL 8.0. The new plugin is also made the default (can be configured by changing default_authentication_plugin.

Why? Phasing out SHA1

As Oracle said in the blog post to annouce this change they want to move to a more secure hashing algorithm (SHA256). Which I think is a good reason to do this.

Adding salt

Adding a …

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How is automation impacting the dba role?

via GIPHY I was at a dinner party recently, and talking with some colleagues. I had worked with them years back on Oracle systems. One colleague Maria said she really enjoyed my newsletter. Join 38,000 others and follow Sean Hull on twitter @hullsean. She went on to say how much has changed in the last …

Continue reading "How is automation impacting the dba role?"


In this blog post, we’ll provide an overview of the new MySQL 8.0 RESOURCE_GROUP feature.

One great new feature introduced in MySQL 8.0 that – from my point of view – requires attention is RESOURCE_GROUP.

Short disclaimer: I want to point out that MySQL 8.0 is not GA yet, so it is possible for the MySQL 8.0 RESOURCE_GROUP implementation to change in features and/or behavior.

I’ve used MySQL Community Server 8.0 RC, and everything mentioned below applies to this MySQL version.

In this post, I will quickly look at this feature and summarize what it’s for, how it makes the DBA’s life a little bit easier and highlight some known limitations.

The MySQL documentation describes it as follows:

“MySQL supports creation and …

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CPU Utilization is Not a Useful Metric

Once upon a time CPU utilization was quite a useful metric. Following are the output of several tools that provide CPU utilization metrics:


top reports a load of 1.66.

Is this correct? No. The correct load number is probably closer to 2.4.

# top -b -n 1| head -20
top - 11:27:45 up 151 days,  1:55,  7 users,  load average: 1.66, 1.84, 1.88
Tasks: 389 total,   3 running, 386 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.7%us, 20.6%sy,  1.2%ni, 77.3%id,  0.1%wa,  0.0%hi,  0.1%si,  0.0%st
Mem:  32639636k total, 32206476k used,   433160k free,   235732k buffers
Swap: 16359420k total, 10285664k used,  6073756k free,  2354840k cached

16702 root      20   0 8274m 5.0g 5.0g S 85.1 16.1  59164:55 VirtualBox
 4657 root      20   0  9.8g 5.2g 5.1g S 45.5 16.6  26518:13 VirtualBox
 6239 root      20   0  9.8g 5.1g 5.1g S 39.6 16.5  31200:52 VirtualBox
27070 root …
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Moving data in real-time into Amazon Redshift – The power of heterogeneous Tungsten Replication

Amazon Redshift has been providing scalable, quick-to-access analytics platforms for many years, but the question remains: how do you get the data from your existing datastore into Redshift for processing? Tungsten Replicator provides real-time movement of data from Oracle and MySQL into Amazon Redshift, including flexible data handling, translation and long-term change data capture.

In our webinar, Wednesday, December 13th, we will review:

  • How Amazon Redshift replication works
  • Deployment from MySQL or Oracle
  • Deployment from Amazon RDS
  • Provisioning/seeding the original information
  • Filtering and accounting for data differences
  • Data concentration/aggregation with single-schema …
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InnoDB Cluster: setting up Production… for disaster! (2/2)

Ok, so now we’re got our InnoDB Cluster a-clustering, MySQL Router a-routing, now we need some disaster to be a-disaster-recovering…

A foreword first.

If you’re looking to use Enterprise Backup to recover a single node and restore that node back into an existing InnoDB Cluster, LeFred takes you through that one nicely here.

Preparing for backup

On our single primary server, the one that allows write, which was ic2/ in my case:

mysql -uroot -poracle << EOF 
SET sql_log_bin = OFF; 
 create user 'backup'@'%' identified by 'oracle';
 grant all on *.* to 'backup'@'%';
SET sql_log_bin = ON; 

Let’s create something to backup (if you haven’t already done so of course):

mysqlsh --uri …
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InnoDB Cluster: setting up Production… for disaster! (1/2)

Want to setup InnoDB Cluster and be prepared for a Disaster Recovery scenario? Get ready:

Here’s a way to set up InnoDB Cluster using the 3 environments, on Oracle Linux 7.2, 5.7.19 MySQL Commercial Server, MySQL Shell 8.0.3 DMR, MySQL Router. As this is the first blog post for a complete disaster recovery scenario of InnoDB Cluster, we’ll also be installing MySQL Enterprise Backup.

If you’re new to InnoDB Cluster then I’d highly recommend looking at the following to understand how it works and what Group Replication, Shell & Router are.:

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