ODBC Server Reference Manual

HP NonStop ODBC Server Mapping Tables
HP NonStop ODBC Server Reference Manual—429151-002
8-7
Data Types
Data Types
The NonStop ODBC Server logical data types described in this section are as follows:
Restoring Tables
A NonStop ODBC Server customized catalog is a NonStop SQL/MP catalog that has
been modified using the NOSUTIL INSTALL statement or the equivalent NonStop
ODBC server CREATE DATABASE command. Customization of the system catalog,
as opposed to a user catalog, reflects the fact that configuration data is found only in
the system catalog. The NonStop ODBC Server mapping tables in the user catalog are
a subset of the NonStop ODBC Server mapping and configuration tables in the system
catalog. The concept of restoring is, however, common to both. Restoring is the act of
detecting missing tables, missing entity description rows in these tables, or missing
foreign references in these tables, and then performing the necessary actions to
correct the detected error in mapping or configuration.
The REFRESH statement is used to perform this process of restoration. REFRESH
requires that the specified catalog is a customized catalog; that is, an entity description
for this catalog exists in the system's ZNSDB database mapping table. An implicit
requirement is that the specified catalog is a NonStop SQL/MP catalog. REFRESH
begins by searching for each of the tables it uses for storing configuration and mapping
data and their associated views and indexes, and re-creating the objects. REFRESH
then performs a sequence of scans through these NonStop ODBC Server tables,
removing foreign references that cannot be found and adding references for objects in
the underlying NonStop SQL/MP catalog not registered in the NonStop ODBC Server
tables.
NonStop ODBC Server configuration and mapping tables are treated by NonStop
SQL/MP as user tables. For this reason, it is possible for the tables to be accidently
deleted or modified, requiring REFRESH to correct the problems. Additionally, because
the NonStop ODBC Server configuration and mapping tables are not updated
automatically when DDL is performed on the NonStop SQL/MP catalog, REFRESH is
needed to update the NonStop ODBC Server tables. When the only discrepancy is the
mapping entry for a table, index, or view, object-specific commands, ADD and
REMOVE, are provided to limit the restoration integrity to less than a complete
REFRESH action sequence.
Data Type Meaning
INT (2) 2-byte integer
INT (4) 4-byte integer
INT (8) 8-byte integer
CHAR (n) Fixed-length character string of n bytes
VARCHAR (n) Variable-length character string of n bytes preceded by a 2-byte integer
indicating the length of the string
TIMESTAMP NonStop SQL/MP data type DATETIME YEAR TO FRACTION