SQL/MX Comparison Guide for SQL/MP Users

DML Features
HP NonStop SQL/MX Comparison Guide for SQL/MP Users—523735-003
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Floating-Point Data Types
NonStop SQL/MX returns a warning indicating that you selected an unsupported data
type with undefined contents. If you try to use the unsupported data type in any sort of
expression, NonStop SQL/MX returns an error.
Floating-Point Data Types
NonStop SQL/MP supports floating-point data types of FLOAT, REAL, and DOUBLE
PRECISION. A column in an SQL/MP table declared with a floating-point data type is
stored in Tandem floating-point format, and all computations on it are done assuming
that.
In previous releases of NonStop SQL/MX, if you want an application to input or output
a date-time or interval value, you must cast it to STRING data type and then input or
output it to or from NonStop SQL/MP.This makes the use of date-time or interval data
types cumbersome in application programs and is not ANSI compliant.
SQL/MX tables now store columns in IEEE floating-point format, as data types of
FLOAT, REAL, and DOUBLE PRECISION. This allows input and output of data from
and to application host variables in Tandem or IEEE floating-point.
NonStop SQL/MX can select data from both SQL/MX and SQL/MP tables. The
returned data from mxci is always in IEEE format. The returned data in an embedded
program can be in IEEE or Tandem format.
NonStop SQL/MX does not allow any column of the partitioning key of a partitionable
table or index to be float data type. If there is no partitioning key specified, the
clustering key becomes the partitioning key.
For information about how SQL/MX floating-point data types, see “Numeric Data
Types” in the SQL/MX Reference Manual.
File Types
SQL/MP tables can have one of three physical file organizations: key-sequenced,
entry-sequenced, or relative and can be partitioned. You can access these types of
SQL/MP files through NonStop SQL/MX:
•
Key-sequenced tables with or without partitions
•
Entry-sequenced tables that are not partitioned
You cannot access these types of SQL/MP files through NonStop SQL/MX:
•
Entry-sequenced tables that are partitioned
•
Relative tables
For more information about SQL/MP file organizations, see the SQL/MP Reference
Manual.