[HttpFoundation] fix PDO session handler under high concurrency#10652

Merged

fabpot merged 3 commits intosymfony:2.3from

Tobion:fix-pdo-session-concurrency

Apr 11, 2014

Commits on Apr 8, 2014

[HttpFoundation] fix PDO session handler under high concurrency
Tobion
committed
[HttpFoundation] use MERGE SQL for MS SQL Server session storage
Tobion
committed

Commits on Apr 9, 2014

[HttpFoundation] use insert or replace for sqlite session handler
Tobion
committed