diff --git a/pages/总复习2023t1.md b/pages/总复习2023t1.md
index 51ba6df..15e58da 100644
--- a/pages/总复习2023t1.md
+++ b/pages/总复习2023t1.md
@@ -1006,29 +1006,30 @@
 							- The instances of a potential subclass participate in a relationship unique to that subclass.
 			- DONE Block 3
 				- DONE DB transaction management
-					- anomalies
-					- DONE ACID (Atomicity, Consistency, Isolation, Durability): A set of properties that guarantee the reliability and integrity of database transactions. #flashcard
-						- Atomicity: :-> The property that ensures a transaction is treated as a single, indivisible unit of work. It either executes all its operations successfully or rolls back to the initial state if any operation fails.
-						- Consistency: :-> The property that ensures a transaction transforms the database from one consistent state to another consistent state. It maintains data integrity and adheres to defined business rules.
-						- Isolation: :-> The property that ensures concurrent transactions do not interfere with each other. Each transaction operates in isolation until it completes, preventing interference or conflicts.
-						- Durability: :-> The property that ensures committed changes made by a transaction are permanently saved and will survive any subsequent system failures or crashes.
-					- DONE Concurrency control
-						- DONE Meaning of serialisability.
-						- DONE How locking can ensure serialisability.
-							- Locking achieves serializability by using locks to control access to
-							  shared resources (e.g., database objects like tables or rows) and
-							  prevent conflicts between concurrent transactions.
-						- DONE 2PL
-							- In the 2PL protocol, transactions acquire and release locks on database
-							  objects (e.g., tables, rows) in two distinct phases: the growing phase
-							  and the shrinking phase.
-						- DONE Deadlock and how it can be resolved.
+					- LATER anomalies
+						- DONE Deadlock and how it can be resolved. #flashcard
 							- A deadlock is a situation in which two or more transactions are unable
 							  to proceed because each is waiting for a resource held by the other,
 							  resulting in a circular dependency and a system halt. It is a form of
 							  resource contention that can occur in concurrent systems, including
 							  database management systems.
-						- DONE How timestamping can ensure serialisability.
+					- DONE ACID (Atomicity, Consistency, Isolation, Durability): A set of properties that guarantee the reliability and integrity of database transactions. #flashcard
+					  collapsed:: true
+						- Atomicity: :-> The property that ensures a transaction is treated as a single, indivisible unit of work. It either executes all its operations successfully or rolls back to the initial state if any operation fails.
+						- Consistency: :-> The property that ensures a transaction transforms the database from one consistent state to another consistent state. It maintains data integrity and adheres to defined business rules.
+						- Isolation: :-> The property that ensures concurrent transactions do not interfere with each other. Each transaction operates in isolation until it completes, preventing interference or conflicts.
+						- Durability: :-> The property that ensures committed changes made by a transaction are permanently saved and will survive any subsequent system failures or crashes.
+					- DONE Concurrency control
+						- LATER Meaning of serialisability.
+						- DONE How locking can ensure serialisability. #flashcard
+							- Locking achieves serializability by using locks to control access to
+							  shared resources (e.g., database objects like tables or rows) and
+							  prevent conflicts between concurrent transactions.
+						- DONE 2PL #flashcard
+							- In the 2PL protocol, transactions acquire and release locks on database
+							  objects (e.g., tables, rows) in two distinct phases: the growing phase
+							  and the shrinking phase.
+						- DONE How timestamping can ensure serialisability. #flashcard
 							- By using transaction timestamps and enforcing the read and write
 							  validation checks, concurrency control mechanisms can ensure that
 							  transactions are executed in a way that maintains data consistency and
@@ -1049,7 +1050,7 @@
 								- Checkpoint records.
 								- Often used for other purposes (for example, auditing).
 							- For autiding
-						- DONE Purpose of checkpointing.
+						- DONE Purpose of checkpointing. #flashcard
 							- When failure occurs, redo all transactions that
 							  committed since the checkpoint and undo all
 							  transactions active at time of crash.