enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Block Range Index - Wikipedia

    en.wikipedia.org/wiki/Block_Range_Index

    This makes them efficient, but limits them to particular vendors. So far PostgreSQL is the only vendor to have announced a live product with this specific feature, in PostgreSQL 9.5. [ 3 ] [ 4 ] Other vendors have described some similar features, [ 2 ] including Oracle , [ 5 ] [ 6 ] Netezza 'zone maps', [ 7 ] Infobright 'data packs', [ 8 ...

  3. Select (SQL) - Wikipedia

    en.wikipedia.org/wiki/Select_(SQL)

    SELECT * FROM (SELECT ROW_NUMBER OVER (ORDER BY sort_key ASC) AS row_number, columns FROM tablename) AS foo WHERE row_number <= 10 ROW_NUMBER can be non-deterministic : if sort_key is not unique, each time you run the query it is possible to get different row numbers assigned to any rows where sort_key is the same.

  4. Codd's 12 rules - Wikipedia

    en.wikipedia.org/wiki/Codd's_12_rules

    Codd's twelve rules [1] are a set of thirteen rules (numbered zero to twelve) proposed by Edgar F. Codd, a pioneer of the relational model for databases, designed to define what is required from a database management system in order for it to be considered relational, i.e., a relational database management system (RDBMS).

  5. Relational database - Wikipedia

    en.wikipedia.org/wiki/Relational_database

    The rows represent instances of that type of entity (such as "Lee" or "chair") and the columns represent values attributed to that instance (such as address or price). For example, each row of a class table corresponds to a class, and a class corresponds to multiple students, so the relationship between the class table and the student table is ...

  6. Comparison of relational database management systems - Wikipedia

    en.wikipedia.org/wiki/Comparison_of_relational...

    Max row size Max columns per row Max Blob/Clob size Max CHAR size Max NUMBER size Min DATE value Max DATE value Max column name size Informix Dynamic Server: ≈0.5 YB 12: ≈0,5YB 12: 32,765 bytes (exclusive of large objects) 32,765 4 TB 32,765 14: 10 125 13: 01/01/0001 10: 12/31/9999 128 bytes Ingres: Unlimited Unlimited 256 KB 1,024 2 GB 32 ...

  7. Help:Advanced table formatting - Wikipedia

    en.wikipedia.org/wiki/Help:Advanced_table_formatting

    Cut cells into parts: Instead of trying to make a super-cell that spans rows/columns, split it into smaller cells while leaving some cells intentionally empty. Use a non-breaking space with &nbsp; or {} in empty cells to maintain the table structure. Custom CSS styling: Override the wikitable class defaults by explicitly specifying:

  8. Entity–attribute–value model - Wikipedia

    en.wikipedia.org/wiki/Entity–attribute–value...

    SQL Server has limitations on row size if attempting to change the storage format of a column: the total contents of all atomic-datatype columns, sparse and non-sparse, in a row that contain data cannot exceed 8016 bytes if that table contains a sparse column for the data to be automatically copied over.

  9. Join (SQL) - Wikipedia

    en.wikipedia.org/wiki/Join_(SQL)

    An inner join (or join) requires each row in the two joined tables to have matching column values, and is a commonly used join operation in applications but should not be assumed to be the best choice in all situations. Inner join creates a new result table by combining column values of two tables (A and B) based upon the join-predicate.