Foundations

Joins, Join Conditions, Filters and Join Types

1 Comment / Oracle / By / February 11, 2010 / , , , , , ,

Joins A join is a query that combines rows from two or more tables. Oracle performs a join whenever multiple tables appear in the FROM clause of the query. Below is a SQL join statement, legacy syntax and ANSI/ISO syntax (also referred as new join syntax, was first introduced in Oracle 9i release) in a …

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Optimizer Index Access Paths

Leave a Comment / Oracle / By / November 11, 2009 / , , , , , , ,

Access paths are ways in which data is retrieved from the database. In general, index access paths should be used for statements that retrieve a small subset of table rows, while full scans are more efficient when accessing a large portion of the table. Online transaction processing (OLTP) applications, which consist of short-running SQL statements …

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