Method transact_start

Method: transact_start()

Turkce Dokumantasyon | English Documentation

Category: Transaction & Concurrency Methods
Submodule: AmberDB::Transact
Entry Type: Transaction Initialization

---

1. Definition and Overview

transact_start() initiates an ACID-compliant multi-table transaction. It creates an active disk-backed undo-journal file under dbstore/txn/ and activates Strict 2-Phase Locking (Strict 2PL). All subsequent record mutations will record their pre-modification states to the journal before modifying physical .db and index files on disk.

---

2. Syntax and Signature

$adb->transact_start();

---

3. Practical Code Example

$adb->transact_start();
eval {
    # Atomic multi-table updates
    $adb->modify_id("inventory", @stock_record);
    $adb->insert_id("orders", @order_record);
    $adb->transact_end(); # Commit changes
};
if ($@) {
    $adb->transact_rollback(); # Revert on failure
}

---

4. See Also

• Concept: Strict 2PL Locking
• Concept: Undo Journal Rollback
• Method: transact_end
• Method: transact_rollback
• File: .txn (Undo Journal)