MP Users

Data Definition Language (DDL) Differences

HP NonStop SQL/MX Comparison Guide for SQL/MP Users—523735-003

6-4

Tables

You create constraints on an SQL/MX table with the CREATE TABLE and ALTER

TABLE ADD CONSTRAINT statements. You create constraints on SQL/MP tables with

the CREATE CONSTRAINT statement.

Clustering Keys

You assign a clustering key for an SQL/MX table by using the STORE BY clause of the

CREATE TABLE statement. If you enter STORE BY PRIMARY KEY, NonStop SQL/MX

bases the clustering key on the primary key. The STORE BY clause determines the

order of rows in the physical file and affects how you can partition the file.

You assign a clustering key for an SQL/MP table by using the CLUSTERING KEY

clause of the CREATE TABLE statement, listing the columns that will be used for this

key. SQL/MP stores rows in ascending or descending order, as you specify. You

cannot control the order of rows in the physical file.

Table Attributes

NonStop SQL/MX allows you to set these table attributes: ALLOCATE,

AUDITCOMPRESS, BLOCKSIZE, CLEARONPURGE, EXTENT, and MAXEXTENTS.

NonStop SQL/MP allows you to set these table attributes: ALLOCATE, AUDIT,

AUDITCOMPRESS, BLOCKSIZE, BUFFERED, CLEARONPURGE, DCOMPRESS,

EXTENT, FORMAT, ICOMPRESS, LOCKLENGTH, MAXEXTENTS, NOPURGEUNTIL,

RECLENGTH, TABLECODE, and VERIFIEDWRITES.

File Types

You can access these type 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 type of SQL/MP files through NonStop SQL/MX:

•

Entry-sequenced tables that are partitioned

•

Relative tables

Constraints

You create constraints on SQL/MX tables with the CREATE TABLE statement, and you

can add or drop constraints with the ALTER TABLE statement. For more information,

see “SQL/MX Language Elements” in the SQL/MX Reference Manual.

To create constraints on an SQL/MP table, use the SQL/MP CREATE CONSTRAINT

statement when you create the table. To drop constraints on an SQL/MP table, use the

SQL/MP DROP statement.