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@ -1005,25 +1005,21 @@
- The instances of a potential subclass participate in a relationship unique to that subclass. - The instances of a potential subclass participate in a relationship unique to that subclass.
- DONE Block 3 - DONE Block 3
- DONE DB transaction management - DONE DB transaction management
- DONE anomalies - DONE Deadlock and how it can be resolved. #flashcard
:LOGBOOK: id:: 64841da4-d8ce-46f5-bbe6-4dee620cde75
CLOCK: [2023-06-14 Wed 16:41:52]--[2023-06-14 Wed 16:49:14] => 00:07:22 - A deadlock is a situation in which two or more transactions are unable
:END: to proceed because each is waiting for a resource held by the other,
- DONE Deadlock and how it can be resolved. #flashcard resulting in a circular dependency and a system halt. It is a form of
id:: 64841da4-d8ce-46f5-bbe6-4dee620cde75 resource contention that can occur in concurrent systems, including
- A deadlock is a situation in which two or more transactions are unable database management systems.
to proceed because each is waiting for a resource held by the other, - Example:
resulting in a circular dependency and a system halt. It is a form of - Cascading rollback #flashcard
resource contention that can occur in concurrent systems, including id:: 64897f0b-dda6-4cc3-a9c3-cf630bcb0658
database management systems. - Cascading Rollback: a transaction (T1) causes a
- Example: failure and a rollback must be performed. Other
- Cascading rollback #flashcard transactions dependent on T1's actions must also
id:: 64897f0b-dda6-4cc3-a9c3-cf630bcb0658 be rollbacked, thus causing a cascading effect.
- Cascading Rollback: a transaction (T1) causes a - One transaction's failure causes many to fail.
failure and a rollback must be performed. Other
transactions dependent on T1's actions must also
be rollbacked, thus causing a cascading effect.
- One transaction's failure causes many to fail.
- DONE ACID (Atomicity, Consistency, Isolation, Durability): A set of properties that guarantee the reliability and integrity of database transactions. #flashcard - DONE ACID (Atomicity, Consistency, Isolation, Durability): A set of properties that guarantee the reliability and integrity of database transactions. #flashcard
id:: 64841da4-0055-4d34-9f61-1402ff068ec7 id:: 64841da4-0055-4d34-9f61-1402ff068ec7
collapsed:: true collapsed:: true
@ -1102,6 +1098,7 @@
id:: 64842000-c15a-4b8f-95c3-d6c6e49e4af0 id:: 64842000-c15a-4b8f-95c3-d6c6e49e4af0
- Fourth Normal Form (4NF): 4NF is a further refinement of BCNF that ensures that _a table does not contain any multi-valued dependencies._ - Fourth Normal Form (4NF): 4NF is a further refinement of BCNF that ensures that _a table does not contain any multi-valued dependencies._
- Fifth Normal Form (5NF): 5NF is the highest level of normalization and involves decomposing a table into smaller tables to _remove data redundancy and improve data integrity._ - Fifth Normal Form (5NF): 5NF is the highest level of normalization and involves decomposing a table into smaller tables to _remove data redundancy and improve data integrity._
- Anomaly
- LATER Block 4 - LATER Block 4
- DONE Distributed DBMS - DONE Distributed DBMS
- DONE client server arch #flashcard - DONE client server arch #flashcard