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  2. ACID - Wikipedia

    en.wikipedia.org/wiki/ACID

    The following examples further illustrate the ACID properties. In these examples, the database table has two columns, A and B. An integrity constraint requires that the value in A and the value in B must sum to 100. The following SQL code creates a table as described above:

  3. Consistency (database systems) - Wikipedia

    en.wikipedia.org/wiki/Consistency_(database_systems)

    The CAP theorem is based on three trade-offs, one of which is "atomic consistency" (shortened to "consistency" for the acronym), about which the authors note, "Discussing atomic consistency is somewhat different than talking about an ACID database, as database consistency refers to transactions, while atomic consistency refers only to a property of a single request/response operation sequence.

  4. Database transaction - Wikipedia

    en.wikipedia.org/wiki/Database_transaction

    A database transaction symbolizes a unit of work, performed within a database management system (or similar system) against a database, that is treated in a coherent and reliable way independent of other transactions. A transaction generally represents any change in a database. Transactions in a database environment have two main purposes:

  5. Atomicity (database systems) - Wikipedia

    en.wikipedia.org/wiki/Atomicity_(database_systems)

    In database systems, atomicity (/ ˌ æ t ə ˈ m ɪ s ə t i /; from Ancient Greek: ἄτομος, romanized: átomos, lit. 'undividable') is one of the ACID (Atomicity, Consistency, Isolation, Durability) transaction properties. An atomic transaction is an indivisible and irreducible series of database operations such that either all occur ...

  6. Durability (database systems) - Wikipedia

    en.wikipedia.org/wiki/Durability_(database_systems)

    In database systems, durability is the ACID property that guarantees that the effects of transactions that have been committed will survive permanently, even in cases of failures, [1] including incidents and catastrophic events. For example, if a flight booking reports that a seat has successfully been booked, then the seat will remain booked ...

  7. Isolation (database systems) - Wikipedia

    en.wikipedia.org/wiki/Isolation_(database_systems)

    In order to access a database object a transaction first needs to acquire a lock for this object. Depending on the access operation type (e.g., reading or writing an object) and on the lock type, acquiring the lock may be blocked and postponed, if another transaction is holding a lock for that object.

  8. CAP theorem - Wikipedia

    en.wikipedia.org/wiki/CAP_theorem

    Database systems designed with traditional ACID guarantees in mind such as RDBMS choose consistency over availability, whereas systems designed around the BASE philosophy, common in the NoSQL movement for example, choose availability over consistency. [9]

  9. Data integrity - Wikipedia

    en.wikipedia.org/wiki/Data_integrity

    An example of a data-integrity mechanism is the parent-and-child relationship of related records. If a parent record owns one or more related child records all of the referential integrity processes are handled by the database itself, which automatically ensures the accuracy and integrity of the data so that no child record can exist without a parent (also called being orphaned) and that no ...