Ora Training Blog

Oracle PL/SQL Quick Reference   PL/SQL Block Structure DECLARE –Optional   –Variables, Cursors, User-defined exceptions BEGIN –Mandatory   –SQL statements   –PL/SQL statements EXCEPTION –Optional   –Actions to perform when errors occur END; –Mandatory

Oracle SQL Quick Reference SELECT Query Statement SELECT [DISTINCT] {*, column [alias],…} FROM table WHERE condition(s)] ORDER BY {column, exp, alias} [ASC|DESC]] NOTE: Avoid using DISTINCT with large table as it first does sorting of all the rows and then eliminates duplicate rows, so need a full table scan and thus it’s very slow. ORDER […]

Oracle SQL Tuning Tips consideration when writing an SQL statement is that it returns a correct result. The second is that it be the most efficient for a given situation.  You can use many different SQL statements to achieve the same result. It is often the case that only one statement will be the most […]