SQL/MX 3.2 Management Manual (H06.25+, J06.14+)

Table Of Contents
Table 1 SQL/MX Metadata Schemas (continued)
Schema ContentsSchema Name
example, a list of Guardian locations for a table’s
partitions).
The SYSTEM_DEFAULTS table resides in the system catalog
under this schema. This user metadata table contains the
SYSTEM_DEFAULTS_SCHEMA
default settings for options and other attributes used with
MXCI commands and SQL/MX statements.
Five NonStop SQL/MX Connectivity Service (MXCS) tables
reside in the system catalog under this schema. For more
information, see the SQL/MX Reference Manual.
MXCS_SCHEMA
The stored procedure VALIDATEROUTINE and
VALIDATEROUTINE2 reside in the system catalog under
this schema. This schema contains no metadata tables.
SYSTEM_SQLJ_SCHEMA
One set of schema definition tables resides in each user
catalog under this schema. These system metadata tables
DEFINITION_SCHEMA _VERSION_vernum
are created for a given catalog when the first CREATE
SCHEMA statement is executed for the catalog. They store
and maintain definitions of the objects in the catalog.
Three histogram tables (HISTOGRAMS,
HISTOGRAM_INTERVALS, and
user schemas
HISTOGRAM_FREQ_INTERVAL) reside in each user schema.
These user metadata tables describe how data is distributed
with respect to a column or group of columns within a table.
The optimizer uses these statistics to create efficient access
plans.
The SYSTEM_SECURITY_SCHEMA tables reside in
NONSTOP_SQLMX_nodename. This metadata contains
SYSTEM_SECURITY_SCHEMA
system metadata that holds node-wide security related
information.
NOTE: VALIDATEROUTINE2 is the internal SPJ of system_SQLJ_schema that is supported on
systems running J06.05 and later J-series RVUs and H06.16 and later H-series RVUs. However,
VALIDATEROUTINE is used on systems running J06.04 and earlier J-series RVUS and H06.15 and
earlier H-series RVUs.
For more information, see “Querying SQL/MX Metadata” (page 104) and the SQL/MX Reference
Manual.
SQL/MX Database Object Types
Table 2 (page 23)describes SQL/MX object types. For more information about SQL/MP objects,
see the SQL/MP Installation and Management Guide and the SQL/MP Reference Manual.
Table 2 SQL/MX Object Types
DescriptionSQL/MX Object Type
A logical representation of data in which a set of records is represented as a
sequence of rows, and the set of fields common to all rows is represented by columns.
Table
A column is a set of values of the same data type with the same definition. The
intersection of a row and column represents the data value of a particular field in a
particular record. Every table must have one or more columns, but the number of
rows can be zero. There is no inherent order of rows within a table.
An SQL/MX table is described in an SQL/MX schema and its data is stored in one
or more physical files in the Guardian environment. An SQL/MX table name must
be a fully qualified ANSI name of the form:
catalog-name.schema-name.object-name
A table that has a logical name and an associated physical file that resides in the
Guardian environment. A view is derived from a query that determines how to create
View
SQL/MX Database Object Types 23