Snippet Name: SELECT with SAMPLE clause Description: The sample clause can be used to return only a percentage of matching records in a query. Also see:» TABLE: Using Select Statement With Data » SELECT: Case insensitive search » SELECT: Partition Select » SELECT: Select For Update » SELECT: Using Functions » SELECT: Get DISTINCT or UNIQUE values » SELECT: Get UNIQUE and DISTINCT values » SELECT: Scalar Select » SELECT with HAVING Clause » SELECT with GROUP BY Clause » SELECT with WHERE Clause » SELECT placement » SELECT into a table » SELECT name columns » SELECT » UPDATE: Update from a SELECT statement » Inserting into SELECT statement » INSERT with Select Comment: (none) Language: PL/SQL Highlight Mode: PLSQL Last Modified: March 10th, 2009
Description: The sample clause can be used to return only a percentage of matching records in a query.
Also see:» TABLE: Using Select Statement With Data » SELECT: Case insensitive search » SELECT: Partition Select » SELECT: Select For Update » SELECT: Using Functions » SELECT: Get DISTINCT or UNIQUE values » SELECT: Get UNIQUE and DISTINCT values » SELECT: Scalar Select » SELECT with HAVING Clause » SELECT with GROUP BY Clause » SELECT with WHERE Clause » SELECT placement » SELECT into a table » SELECT name columns » SELECT » UPDATE: Update from a SELECT statement » Inserting into SELECT statement » INSERT with Select
SELECT * FROM <table_name> SAMPLE (percentage_of_rows); -- create a sample set CREATE TABLE test_set AS SELECT object_name FROM all_objects WHERE SUBSTR(object_name,1,1) BETWEEN 'A' AND 'N'; -- see count of all records SELECT COUNT(*) FROM test_set; - SELECT 20% OF records SELECT COUNT(*) * 0.2 FROM test_set; - SELECT 75% OF records SELECT COUNT(*) * 0.75 FROM test_set;
