The dangers of upgrading

[musicmaster]

I am having upgrade problems too that no one seems able to solve (see here: http://www.prestashop.com/forums/topic/275610-mysql-server-has-gone-away-with-upgrade-149-155/). So I did some analysis.

 

I am using PS 1.4.9. That shop was upgraded some time ago from a previous version (I think 1.4.6 but I am not sure). Now I can upgrade a fresh install of 1.4.9 but not my version. I analyzed whether it is the database or the files and it appears that it is the database (fresh install with old database give same problems). 

 

So I did the following analysis:

 - both from the fresh shop and my old shop I exported the structure of the database in PHPMyAdmin. 

 - next I cleaned up the the structure file of my old database by removing all tables that had been inserted later with the addition of modules.

 - now the files were equal enough that I could compare them. I did this with the Command line (MSDos) command "FC fresh.sql old.sql > dif.txt"

 - then I could easily analyze the differences.

 

Preliminary results:

 - there was one table where the order of the fields had changed: ps_compare_product

 - two field sizes had changed: in ps_product and in ps_specific_price

 - indexes were a mess. Sometimes the order or type had changed. Also often there was extra naming. For example "PRIMARY KEY (`id_category`,`id_lang`)," had been changed into "UNIQUE KEY `category_lang_index` (`id_category`,`id_lang`)"

 - most differences were auto_increments. I ignored them.

 

I suppose that with each upgrade we get more of those little errors. Quality control at PS seems weak - otherwise these errors wouldn't happen. I assume that many of those difficult to solve errors originate in repeated upgrades. So my advice would be to upgrade seldom and to make big steps at once.

 

As for the Prestashop organization: I hope they finally take all those complaints seriously and dedicate some resources to help people experiencing upgrade problems. They should also have a more structured upgrade procedure:

 - for every version there should be a quality check that repairs all those little differences that I saw

 - after an upgrade the database structure should be exactly the same as with a new install. Now that is obviously not the case.

 

Prestashop is very proud of its two million downloads. I am getting skeptical. Maybe 1.9 million were by people who many times in vain tried to upgrade their shop.

[Jiten rash (away)]

there is a module called "autoupgrade" do u have?

[musicmaster]

Yes, I did use autoupgrade. My whole point is that it is a rather sloppy tool that makes an incomplete upgrade of your database - setting you up for trouble with the next upgrade.

[tuk66]

 - after an upgrade the database structure should be exactly the same as with a new install. Now that is obviously not the case.

Should be but in some cases it is really hard task so I don't assume that it will be reality.