Tag Archive: SQL

Binary Search
  • 23
    Mar

Binary Search

One of the most interesting algorithms of research is binary search algorithm. This is the fastest algorithm (algorithm of binary trees apart) to search a data inside a group of elements. In fact it runs in a worst log2(x) comparisions...

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Nested table
  • 2
    Mar

Nested table

In PL SQL exists an efficient and adaptable collection of data: Nested table. Nested table is similar to one dimensional array but with some differences : An array has declare number of element – Nested table not. The size of...

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Using  Invisible Indexes
  • 27
    Ott

Using Invisible Indexes

Table created. SQL> create index ind_TEST.index_tables on TEST.tables_empty (a) Index created. OWNER                          OBJECT_NAME                    OBJECT_TYPE ------------------------------ ------------------------------ ----------- TEST                           TABLES_EMPTY                   TABLE IND_TEST                       INDEX_TABLES                  INDEX   SQL> exec dbms_stats.gather_table_stats (ownname=>'TEST',tabname=>'TABLES_EMPTY',cascade=>TRUE); PL/SQL procedure successfully completed. SQL>  exec dbms_stats.gather_index_stats (ownname=>'IND_TEST',indname=>'INDEX_TABLES'); PL/SQL procedure successfully completed....

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EXPLICIT CURSORS – modify tables
  • 9
    Lug

EXPLICIT CURSORS – modify tables

In the previous article (cursors overview) we have seen simple examples with SQL statements. You can also use cursor to modify database tables. If we want to use explicit cursor to update or delete data, we need to: -declare the...

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