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  2. Halloween Problem - Wikipedia

    en.wikipedia.org/wiki/Halloween_Problem

    In computing, the Halloween Problem refers to a phenomenon in databases in which an update operation causes a change in the physical location of a row, potentially allowing the row to be visited again later in the same update operation. This could even cause an infinite loop in some cases where updates continually place the updated record ahead ...

  3. Hierarchical and recursive queries in SQL - Wikipedia

    en.wikipedia.org/wiki/Hierarchical_and_recursive...

    In SQL:1999 a recursive (CTE) query may appear anywhere a query is allowed. It's possible, for example, to name the result using CREATE [ RECURSIVE ] VIEW . [ 16 ] Using a CTE inside an INSERT INTO , one can populate a table with data generated from a recursive query; random data generation is possible using this technique without using any ...

  4. Object–relational impedance mismatch - Wikipedia

    en.wikipedia.org/wiki/Object–relational...

    Object–relational impedance mismatch is a set of difficulties going between data in relational data stores and data in domain-driven object models. Relational Database Management Systems (RDBMS) is the standard method for storing data in a dedicated database, while object-oriented (OO) programming is the default method for business-centric design in programming languages.

  5. Query optimization - Wikipedia

    en.wikipedia.org/wiki/Query_optimization

    The search space can become quite large depending on the complexity of the SQL query. There are two types of optimization. These consist of logical optimization—which generates a sequence of relational algebra to solve the query—and physical optimization—which is used to determine the means of carrying out each operation.

  6. List of NP-complete problems - Wikipedia

    en.wikipedia.org/wiki/List_of_NP-complete_problems

    The problem for graphs is NP-complete if the edge lengths are assumed integers. The problem for points on the plane is NP-complete with the discretized Euclidean metric and rectilinear metric. The problem is known to be NP-hard with the (non-discretized) Euclidean metric. [3]: ND22, ND23

  7. Database normalization - Wikipedia

    en.wikipedia.org/wiki/Database_normalization

    To solve the problem, the subjects are extracted into a separate Subject table: [10] Book Title ... Other DBMSs, such as Microsoft SQL Server 2012 and later, let you ...

  8. We’re Obsessed With These 50 Strange Items That Solve Real ...

    www.aol.com/not-average-solutions-50-wacky...

    We've gathered 50 delightfully unconventional products that prove solving life's everyday problems doesn't have to be boring. These aren't your standard household items; they're conversation ...

  9. Count-distinct problem - Wikipedia

    en.wikipedia.org/wiki/Count-distinct_problem

    For example, the weighted estimator proposed by Cohen et al. [5] can be obtained when the continuous max sketches estimator is extended to solve the weighted problem. In particular, the HyperLogLog algorithm [6] can be extended to solve the weighted problem. The extended HyperLogLog algorithm offers the best performance, in terms of statistical ...