public synonym

Public Synonyms in Oracle PL/SQL

Public Synonyms By creating a Public Synonym you allow the user to reference the table name without using the schema owner prefixed on the record name (i.e. SYSADM.PS_VENDOR). This also eliminates the need to perform an ALTER SESSION  command. Example:

How to find tables that do not have a public synonym. Use the following example […]

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combine

Combine Sub Queries in Oracle PL/SQL

Combine Sub Queries in Oracle PL/SQL Separate Sub Queries Most of us do this when we need the most effective date with the most effective sequence.

Combined Sub Queries

This reduces the number of lookup operations the database has to do to one instead of the two in the previous example.

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union all vs union

UNION ALL vs UNION Oracle PL/SQL

Difference between UNION ALL and UNION in Oracle UNION In Oracle the UNION clause delays returning any rows until each portion of the UNION is sorted and merged and duplicates filtered out.

  UNION ALL A UNION ALL  simply returns all rows with out the overhead of sorting, merging and removing duplicates from the results. If […]

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