SQL/MX 3.2.1 Management Manual (H06.26+, J06.15+)

• Use datetime fields carefully:
Datetime operations are expensive.◦
◦ Use datetime fields if datetime arithmetic is needed in an SQL query (for example, where
date-col + interval '1' day > date '2001-09- 11').
◦ Use LARGEINT or CHAR if datetime is needed for storage and retrieval only.
• Where possible, avoid adding columns to a table:
Added columns turn off internal expression optimizations.◦
◦ If you add a column, reload the table.
Accessing an SQL/MP Database From NonStop SQL/MX
From NonStop SQL/MX, you can run queries on an SQL/MP database located on the same node.
Such queries must conform to these guidelines:
• Perform DML operations only. From NonStop SQL/MX, you cannot perform DDL operations
or utility operations on SQL/MP database objects. If you want to perform DDL operations and
utility operations on SQL/MP database objects, you must do so from NonStop SQL/MP.
• Use either valid SQL/MP aliases or Guardian names for SQL/MP objects.
• Make sure that all SQL/MP objects comply with the Guardian security conventions as described
in the SQL/MP Installation and Management Guide.
• You can mix SQL/MP and SQL/MX tables in the same DML statement. You can join an
SQL/MP and SQL/MX table, create a union of them, and insert data from an SQL/MP table
into an SQL/MX table and visa versa.
• You cannot create a view that references both an SQL/MP table and an SQL/MX table.
For more information, see the SQL/MX Comparison Guide for SQL/MP Users.
For instructions and examples on executing DDL statements from SQLCI, see the SQL/MP Installation
and Management Guide and the SQL/MP Reference Manual.
104 Creating an SQL/MX Database