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Diffstat (limited to 'activerecord/CHANGELOG.md')
| -rw-r--r-- | activerecord/CHANGELOG.md | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md index a888b79391..e864e90e6f 100644 --- a/activerecord/CHANGELOG.md +++ b/activerecord/CHANGELOG.md @@ -1,5 +1,27 @@ ## Rails 4.0.0 (unreleased) ## +* Fixing issue #776. + + Memory bloat in transactions is handled by having the transaction hold only + the AR objects which it absolutely needs to know about. These are the AR + objects with callbacks (they need to be updated as soon as something in the + transaction occurs). + + All other AR objects can be updated lazily by keeping a reference to a + TransactionState object. If an AR object gets inside a transaction, then + the transaction will add its TransactionState to the AR object. When the + user makes a call to some attribute on an AR object (which has no + callbacks) associated with a transaction, the AR object will call the + sync_with_transaction_state method and make sure it is up to date with the + transaction. After it has synced with the transaction state, the AR object + will return the attribute that was requested. + + Most of the logic in the changes are used to handle multiple transactions, + in which case the AR object has to recursively follow parent pointers of + TransactionState objects. + + *John Wang* + * Descriptive error message when the necessary AR adapter gem was not found. Fix #7313 |