ALTDBE [ ALLBASE/SQL Database Administration Guide ] MPE/iX 5.5 Documentation
ALLBASE/SQL Database Administration Guide
ALTDBE
Changes the startup parameters for a DBEnvironment.
Scope
SQLUtil Only
SQLUtil Syntax
>> ALTDBE DBEnvironment Name: DBEnvironmentName Maintenance Word:
MaintenanceWord AutoStart Mode (on/off) (opt): AutoStartMode User Mode
(single/multi) (opt): UserMode DDL Enabled (y/n) (opt): DDLEnabled
No. of Runtime Control Block Pages (opt): ControlBlockPages No. of
Data Buffer Pages (opt): DataBufferPages Data Buffer Pages Memory
Resident (y/n) (opt): MemoryResidentEnabled No. of Log Buffer Pages
(opt): LogBufferPages Max. Transactions (opt): MaxTransactions
[MaximumTimeout [SECONDS]]
Maximum Timeout (opt): [ [MINUTES]] Default Timeout
[ ]
[NONE ]
[DefaultTimeout [SECONDS]]
(opt): [ [MINUTES]] Authorize Once per Session (on/off)
[ ]
[MAXIMUM ]
(opt): AuthorizeOnce Alter DBEnvironment Startup Parameters (y/n)?
{Y[es]}
{N[o] }
NOTE You must stop the DBEnvironment before you can issue the ALTDBE
command.
Parameters
DBEnvironmentName is the name of the DBEnvironment whose startup
parameters are to be altered.
MaintenanceWord is the maintenance word of the DBEnvironment.
AutoStartMode is ON to enable auto starting of a multiuser
DBEnvironment session when a CONNECT command is
given. It is OFF to disable this feature. The
default is ON.
UserMode is SINGLE to specify that the DBEnvironment
should be started in single-user mode when
AutoStart is enabled. It is MULTI to specify
multiuser operation. The default is determined
by the value you supply in the START DBE NEW
command. If you do not supply a value, the
default is SINGLE.
DDLEnabled is YES to enable data definition language (DDL),
or NO to disable DDL. The default is YES.
ControlBlockPages is the number of 4096-byte pages to allocate to
the pool of shared memory used by DBCore services
in a multi-user DBEnvironment.
DataBufferPages is the number of 4096-byte data buffer pages for
holding data from tables and indexes during
program execution.
MemoryResidentEnabled is YES to specify that data buffer pages will
remain resident in memory. It is NO to specify
that data buffer pages will not be memory
resident (they will be swapped in and out of
memory as needed by ALLBASE/SQL). The default is
NO.
LogBufferPages
is the number of 512-byte log buffers for holding
log records during program execution.
MaxTransactions is the maximum number of concurrent transactions
to be supported.
MaximumTimeout is an integer literal greater than zero. If the
MaximumTimeout is not qualified by MINUTES,
SECONDS is assumed. If MaximumTimeout is set to
NONE, no timeouts are assumed. The default is
NONE.
DefaultTimeout is an integer literal greater than zero. If the
DefaultTimeout is not qualified by MINUTES,
SECONDS is assumed. If DefaultTimeout is set to
MAXIMUM, its value is the same as MaximumTimeout.
The default value of DefaultTimeout is also
MaximumTimeout.
AuthorizeOnce is set ON to permit users of ISV (independent
software vendor) toolsets to obtain improved
performance with dynamic queries. If you have
preprocessed an application with the (DYNAMIC)
option, or if you are using an ISV toolset, set
this flag ON if you want authorization checks on
your dynamic queries to be performed only the
first time the query is executed during the user
session. Set OFF if you want ALLBASE/SQL to do
authorization checks on a dynamic query each time
it is executed. The default is OFF.
Description
* The ALTDBE command updates the parameters required for
DBEnvironment startup. You are prompted for new values for the
parameters one by one; entering a Return retains the old value.
* Startup parameters have been initially defined by a START DBE NEW
command which creates the DBEnvironment and stores these
parameters in the DBECon file. These parameters will be used when
the DBEnvironment is accessed by either a START DBE or a CONNECT
command.
* Setting the MemoryResidentEnabled flag to YES is useful for
database servers where very little is going on besides database
work, and the database buffers occupy a small fraction of real
memory in the system.
* You get better performance from pseudo-mapped DBEFiles if you set
the MemoryResidentEnabled flag to YES.
* This command can only be executed when the DBEnvironment is not in
use.
* You cannot change archive mode with ALTDBE. Refer to the section
"Choosing an Approach to Backup and Recovery" in the "Backup and
Recovery" chapter.
NOTE Scripts using the ALTDBE command that were prepared for use with
releases of ALLBASE/SQL prior to F.0 will not work with this
release unless you edit them to include responses for the memory
resident data buffer flag, default and maximum user timeout, and
the authorize once per session flag. Scripts using ALTDBE that
were prepared for use with releases of ALLBASE/SQL prior to E.1
will not work unless you edit them to remove the response for
archive mode and include responses for the memory resident data
buffer flag, default and maximum user timeout, and the authorize
once per session flag.
Authorization
You must provide the correct maintenance word or be the DBECreator to use
this command.
Example
>> altdbe
DBEnvironment Name: PartsDBE
Maintenance Word: MaintWd
AutoStart Mode (on/off) (opt): on
User Mode (opt): multi
DDL Enabled (y/n) (opt): yes
No. of Runtime Control Block Pages (opt): 37
No. of Data Buffer Pages (opt): 100
Data Buffer Pages Memory Resident (y/n) (opt): no
No. of Log Buffer Pages (opt): 24
Max. Transactions (opt): 5
Maximum Timeout (opt): 10
Default Timeout (opt): 5
Authorize Once per Session (opt): on
Alter DBEnvironment Startup Parameters (y/n)? yes
DBEnvironment startup parameters altered.
MPE/iX 5.5 Documentation