Configure MySQL 5.6 LONGBLOB for large binary data

The reason for this issue is a change in MySQL 5.6.20 as one could read in the change log:

As a result of the redo log BLOB write limit introduced for MySQL 5.6, the innodb_log_file_size setting should be 10 times larger than the largest BLOB data size found in the rows of your tables plus the length of other variable length fields (VARCHAR, VARBINARY, and TEXT type fields). No action is required if your innodb_log_file_size setting is already sufficiently large or your tables contain no BLOB data.

Set or increase the value of the innodb_log_file_size option in my.ini below the [mysqld] section. Its default value is 48M. Setting it to

Be careful when changing the value of innodb_log_file_size. Follow these steps to do this safely:

  • Shut the server down cleanly and normally.
    Shutting down MySQL may not be as simple as just service mysql stop!
    Following things should be done to shut down mysql server normally and cleanly:

    1. Double check the instance you are going to shutdown!!
    2. Stop Replication
    3. Flush the dirty pages
    4. Check the long running transactions
    5. Dump and reload the buffer pool
  • Move away (don’t delete) the log files, which are named ib_logfile0, ib_logfile1, and so on.
  • Check the error log to ensure there was no problem shutting down.
  • Then restart the server and watch the error log output carefully.
    • There should see InnoDB print messages saying that the log files don’t exist. It will create new ones and then start.
  • Verify that InnoDB is working.
    • If it’s working, then the old log files can be deleted.

What are ORM Frameworks?

ORM is a short form of Object Relational Mapping, means as ORM framework is written specifically in OOP (object-oriented programming) language (like PHP, C#, Java, etc…) and it is like a wrapper around a relational database (like MySQL, PostgreSQL, Oracle, etc…). So, ORM is basically mapping objects to relational tables.

What does an ORM framework do?

The ORM framework generates objects (as in OOP) that virtually map the tables in a database. So, any programmer could use these objects to interact with the database without writing an optimized SQL code.

For example:

We have 2 tables in a database:

  • Products
  • Orders

The ORM framework would create 2 objects corresponding to above tables (like products_object and orders_object) with little configuration, which will handle all the database interaction. So, if you want to add a new product in products table, you would have to use products_object and save() method like below,

You can see that, how much easier an ORM framework can make things. No need to write any SQL syntax. And application code would be very clean.

Some other advantages of using ORM frameworks

1. Syncing between OOP language and the relational database data types is always creating a problem. Sometimes variable data types have to be converted properly to insert into the database. A good ORM framework will take care of these conversions.

2. Using an ORM will create a consistent code base for your application since no SQL statements are written in the code. This makes it easier to write and debug any application, especially if more programmers are using same code base.

3. ORM frameworks will shield your application from SQL injection attacks since the framework will be filtering the data before any operation in the database.

4. Database Abstraction; Switching databases for the application is easier as, ORM will take care of writing all the SQL code, data type conversions etc …

When to use an ORM framework?

An ORM framework becomes more useful as the size and complexity of the project increases. An ORM framework may be overkilling an application on a simple database with 5 tables and 5-6 queries to be used for the application.

Consider the use of ORM when:

  • 3 or more programmers are working on an application.
  • Application database consists of 10+ tables.
  • The application is using 10+ queries.

About 80-90% of application queries can be handled by the ORM generated objects. It is inevitable that at some point straight SQL query is required, which can’t be handled by ORM generated objects.

In fact, ORM frameworks often have their own *QL query language that looks a lot like SQL. Doctrine, a popular PHP based ORM framework has DQL (Doctrine Query Language) and the very popular Hibernate (used in the Java and .Net world) has HQL. Going even further, Hibernate allows writing straight SQL if need be.

ORM Frameworks for PHP programmers

  • CakePHP, ORM, and framework for PHP 5
  • CodeIgniter, a framework that includes an ActiveRecord implementation
  • Doctrine, open source ORM for PHP 5.3.X
  • FuelPHP, ORM, and framework for PHP 5.3. Based on the ActiveRecord pattern.
  • Laravel, a framework that contains an ORM called “Eloquent” an ActiveRecord implementation.
  • Maghead, a database framework designed for PHP7 includes ORM, Sharding, DBAL, SQL Builder tools etc.
  • Propel, ORM and query-toolkit for PHP 5, inspired by Apache Torque
  • Qcodo, ORM, and framework for PHP 5
  • QCubed, A community-driven fork of Qcodo
  • Redbean, ORM layer for PHP 5, creates and maintains tables on the fly
  • Yii, ORM, and framework for PHP 5. Based on the ActiveRecord pattern.
  • Zend Framework, a framework that includes a table data gateway and row data gateway implementations. ZendDb

Best alternative to set a PostgreSQL schema using PHP PDO

To set the PostgreSQL DB connection, schema parameter is not to be included

Is this a good practice? Is there a better way to do this?

In order to specify the default schema you should set the search_path instead.

You can also set the default search_path per database user and in that case the above statement becomes redundant.

Access shell with SSH on cPanel server from Linux

Some of the important server related problems will be solved only using shell access to the server. To access the cPanel server shell using SSH, there must be an SSH client installed on PC. Most of the Linux distros include SSH client software by default. If it is not installed, then it can be easily installed with following commands,

For Ubuntu: apt-get install openssh-client
For CentOS: yum install openssh-clients

After installation, follow these steps to access the cPanel shell with SSH from Linux:

  1. Login to cPanel and go to Security > SSH/Shell Access to generate SSH key pair.
  2. Click Manage SSH Keys > Generate a New Key. You should use a password to protect the key. You will be asked the password each time you use the key.
  3. In Public Keys section click ‘Manage Authorization’ and ‘Authorize’
  4. In Private Keys section click, Vew/Download then download the key (id_dsa or id_rsa) to your PC.
  5. Save it to ~/.ssh directory on your Linux machine under a meaningful name to not overwrite your existing keys for example id_dsa.myjavahost
  6. Now make sure permissions are correct on the key (one-time task) and connect:
  7. Provide the password for the key, set up in step #2

You should be logged in by now.

Using Tooltipster Plugin with jQuery Validation

Any many websites, during the form filling process, we show error messages in tooltips. Today we are trying to achieve the same for our websites.

Prerequisites:

  1. Tooltipster Plugin version 2.1 or 3.0 (The raw code for version 2.1 can be found inside the first jsFiddle below.)
  2. jQuery Validate Plugin

First, initialize the Tooltipster plugin (with any options) on all specific form elements that will display errors:

Second, use Tooltipster’s advanced options along with the success: and errorPlacement: callback functions built into the Validate plugin to automatically show and hide the tooltips as follows:

Note that this code example takes advantage of the new Tooltipster API features released in version 2.1 on 2/12/13

For Tooltipster version 3.0

The latest version of Tooltipster, version 3.0, is supposed to be working more correctly than version 2.1.

That’s fine, except that an animation flicker is now occurring on every single keystroke even when no content has changed. I suppose we could disable the default onkeyup option in jQuery Validate, but when multiple rules are used, the user would not be aware of his data entry violation until after leaving the field or clicking the submit button.

The workaround is to set the updateAnimation option to false.

The Tooltipster developer made the following suggestion to preserve the message update animation in version 3.0, which works very nicely. From within the jQuery Validate plugin’s errorPlacement callback function, this simple code makes sure the error message is not blank and has changed before calling Tooltipster’s show method. This has the added benefit of greatly reducing the number of calls to Tooltipster.