Real nested db transactions

[Juan Basso]

Hey guys,

I changed the core to support real nested transactions when the driver support it. I checked that Sqlite, MySQL and Postgres support it. SQL Server also support, but not with PDO. I made a change that should not affect any app or class that extend the DboSource.

code: https://github.com/jrbasso/cakephp/compare/cakephp:2.2...2.2-nested-transaction

travis: http://travis-ci.org/#!/jrbasso/cakephp/builds/991764

Juan Basso

[Vitor Pacheco]

+1

Juan, really good work!

2012/4/1 Juan Basso <jrb...@gmail.com>

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Vitor Pacheco
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[José Lorenzo Rodríguez]

This is super cool, great work Juan. My only concern is that you do not always want to have checkpoints as they are Somewhat expensive for the database manager.

Sometimes having the ability to fake transactions is enough for the user (and in general for internal CakePHP needs such as loading fixtures)

I would offer the ability of using both types, faked and real transaction nesting and making the fake ones the default. If anyone need a more advanced approach to transactions they can just enable it.

What do you think?

Sent from my iPhone

[mark_story]

How would that work josé? 

-Mark

[José Lorenzo Rodríguez]

That is already there, I added fake nested transaction support in 2.0. I'm just suggesting to make that the default.

Just take a look at the functions Juan modified, the logic behind it is pretty simple: add to a counter each time a transaction is begun, only commit if the same number of commit() calls have been made, and always rollback no matter how deep you are in the transactions tree.

Sent from my iPhone

[Juan Basso]

@mark: the old behavior is the same of when the driver do not support nested transactions. As Jose's explained.

About the default behavior be the fake one, don't you think it is a little annoying or frustrating for users once everything works as "expected", except that it doesn't work with database until you enable it? I guess is a small portion of users that use nested transactions, so if these users are expecting [performance] issues, they can disable it.

Juan Basso

2012/4/1 José Lorenzo Rodríguez <jose...@gmail.com>

[Juan Basso]

I added the option to disable the nested transactions. Also, updated the book.

Code: https://github.com/jrbasso/cakephp/compare/cakephp:2.2...2.2-nested-transaction

Book: https://github.com/jrbasso/docs/compare/cakephp:2.2...2.2-nested-transaction

Juan Basso

[mark_story]

It looks good to me Juan.  I wonder if things like nestedTransaction, logQuery and other properties on the datasources, could/should be moved into the configuration part of the datasource.  Seems like those options are configuration data, and its a pain to have config data in two places.  Perhaps we wait on that until 3.0 though.

-Mark

[ADmad]

I had the same thoughts, it would be better to have nestedTransaction as a config param.

-ADmad