SQL/MX 2.x Database and Application Migration Guide (G06.23+, H06.04+, J06.03+)

Version Management and Interoperability

HP NonStop SQL/MX Database and Application Migration Guide—540435-005

2-15

Compiling Mixed-Version Queries

A mixed-version query can be one of these types:

•

A query that refers to a database object that is partitioned across several nodes

that have different versions of SQL/MX Release 2.x

•

A query that refers to several SQL/MX database objects that have different OSVs

Querying a Database Object Partitioned Across Nodes With

Different MXVs

A mixed-version query from an SQL/MX Release 2.x node can refer to a database

object that is partitioned across nodes running several compatible versions of SQL/MX

Release 2.x. In SQL/MX Releases 2.0, 2.1, and 2.2, the plan version for such a query

is the same as the MXV of the lowest-version node that is referenced.

Querying SQL/MX Database Objects That Have Different

OSVs

If a mixed-version query refers to several SQL/MX database objects that have different

OSVs, the database objects must be compatible with the MXVs of all referenced

nodes. Database objects are compatible with the MXVs of all referenced nodes if the

objects’ OSVs are equal to or higher than the earliest supported schema versions of all

referenced nodes and if the objects’ OSVs are equal to or lower than the MXVs of all

referenced nodes.

A mixed-version query that involves SQL/MX database objects on a lower-version

remote node and current-version database objects on the local node that are

incompatible with the MXV of the remote node is disallowed. For SQL/MX Release 2.x,

all SQL/MX database objects have a version of 1200, and no objects are incompatible

with a lower-version node.

Managing a Mixed-Version Network

You can use different SQL/MX software versions in an Expand network if these

versions are within the supported range. For more information, see Interoperability of

NonStop SQL/MX Releases on page 2-8 and Versions of SQL/MX Software

Components on page 2-9.

When managing a mixed-version network, be aware of these considerations:

•

Reasons for Upgrading All Nodes to the Same Version of SQL/MX Release 2.x on

page 2-16

•

Falling Back a Local SQL/MX Node on page 2-16

•

Falling Back a Remote SQL/MX Node Referenced by an Application on an

SQL/MX Release 2.0, 2.1, or 2.2 Node on page 2-16