When the data is naturally tabular

When the number of nodes are volatile

When the data by nature has sparse attributes

When the data is of low volume and requires a complex star-schema topology

SELECT r1 AS retval FROM tab1 INTERSECT SELECT r2 AS retval FROM tab2

SELECT r1 AS retval FROM tab1 EXCEPT SELECT r2 AS retval FROM tab2

SELECT DISTINCT r1 AS retval FROM tab1, tab2 WHERE r1 <> r2

SELECT r1 AS retval FROM tab1 UNION SELECT r2 AS retval FROM tab2

A table referenced in the FROM clause has no indexed column.

The table referenced in the FROM clause has more than 200 columns.

Two or more tables in the FROM clause have identical column names.

The FROM clause contains two or more tables in the SELECT statement.

Package and function

Function and userexit

Procedure and package

Function and procedure

Define the column MAINID as NOT UPDATABLE

Define the column MAINID as a PRIMARY KEY

Define the column MAINID as a FOREIGN KEY

Define an UPDATE trigger on table TABLEX

COL1 will accept NULL values and can be referenced in another table's foreign key specification.

COL1 will not accept NULL values and cannot be referenced in another tables foreign key specification.

COL1 will not accept NULL values and can be referenced in another tables foreign key specification.

COL1 will accept NULL values and cannot be referenced in another tables foreign key specification.

Summarized queries

Granular transactions

Voluminous historical data

Heterogeneous data sources

CREATE UNIQUE INDEX idx_partno ON parts(part_no)

CREATE UNIQUE INDEX idx_partno ON parts(part_name ASC)

CREATE UNIQUE INDEX idx_partno ON parts(part_name, part_no ASC)

CREATE UNIQUE INDEX idx_partno ON parts(part_no, part_name ASC)

UPDATE stock SET (status = NULL; quantity, price = 0) WHERE item LIKE S%

UPDATE stock SET (status, quantity, price) = (NULL, 0, 0) WHERE item LIKE S%

UPDATE stock SET status = NULL, SET quantity = 0, SET price = 0 WHERE item LIKE 'S%'

UPDATE stock SET (status = NULL), (quantity = 0), (price = 0) WHERE item LIKE S%

What is this customers address?

Does this customer have any unpaid bills?

What is the balance in this customers account?

What are the total sales for each of the last 6 months?