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

Table Of Contents
The COMPILERCONTROLS is the table-valued stored procedure, which is implemented from the
compiler. For more information, see the SQL/MX Reference Manual.
Consequences of Inserting Rows Into the SYSTEM_DEFAULTS Table
Changes you make through the SYSTEM_DEFAULTS table are permanent until changed by a DELETE
statement or another UPDATE statement. However, the values you insert into the SYSTEM_DEFAULTS
table do not affect your current session immediately. You must exit and then reenter the MXCI
session for these values to take effect as system-level default settings. In addition, these insertions
do not affect previously compiled modules until you recompile them.
If an attribute has a value in the SYSTEM_DEFAULTS table and a CONTROL QUERY DEFAULT
statement, a CONTROL TABLE statement, or a SET TABLE statement is issued for that attribute, the
value specified by CONTROL QUERY DEFAULT takes precedence over the value in the
SYSTEM_DEFAULTS table for the current session.
For more information, see the SQL/MX Reference Manual.
System Default Settings to Review After Installing Current Release of
SQL/MX
Alternative Settings for Selected System Defaults
Table 6 (page 68) lists the system defaults that you must review, if changed, after you install the
current release of SQL/MX and before you run your applications. For more information, see the
SQL/MX Reference Manual.
Table 6 Settings for Selected System Defaults (page 1 of 5)
Alternative SettingDefault ValueSystem Default
The value OFF means histograms are only fetched
for columns of a table that are involved in a
statement.
The default value is ON.CACHE_HISTOGRAMS
A value of less than 3600 seconds means the cached
histograms are refreshed more frequently than once
per hour.
The default value is 3600.CACHE_HISTOGRAMS_
REFRESH_INTERVAL
You should set the value of this attribute to the
average value of 4KB block disk cache settings for
all volumes in the system.
The default value is 1024.DP2_CACHE_4096_BLOCKS
The value ON allows FFDC dial-outs to occur when
the compiler terminates abnormally or detects an
internal error.
The default value is OFF.FFDC_DIALOUTS_FOR_ MXCMP
The value IEEE means that the IEEE float format is to
be used.
The default value is IEEE.FLOATTYPE
Any disk volume to be used tor UPDATE STATISTICS
temporary files.
For SQL/MX tables, the
default is a blank. If you do
HIST_SCRATCH_VOL
For more information, see the SQL/MX Reference
Manual.
not set this value, NonStop
SQL/MX uses the default
volume specified by the
_DEFAULTS define for
SQL/MX tables and the
volume of the table’s primary
partition for SQL/MP tables.
The value NSK is appropriate if the system uses
physical Guardian names (NSK). The NSK setting
The default value is ANSI.NAMETYPE
applies to the resolution of unqualified SQL/MP
object names.
68 Reviewing and Setting System Defaults