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The START DBE NEWLOG statement establishes a connection with a given
DBEnvironment and creates one or two new log files for that DBEnvironment. It
establishes a set of startup parameters that apply to this and all subsequent
connections until all connections to the DBEnvironment have been
terminated. Any start up parameters not explicitly specified are
taken from the DBECon file except the enabling of audit logging.
This statement reinitializes log file(s) when you need to change
the size, invoke a dual logging or startup, or alter audit logging.
ISQL or Application Programs
START DBE 'DBEnvironmentName' [AS 'ConnectionName'][MULTI]NEWLOG
[{ARCHIVE
DUAL
AUDIT}[...] LOG
BUFFER = (DataBufferPages, LogBufferPages)
TRANSACTION = MaxTransactions
MAXIMUM TIMEOUT = {TimeoutValue [SECONDS
MINUTES]
NONE }
DEFAULT TIMEOUT = {TimeoutValue [SECONDS
MINUTES]
MAXIMUM }
RUN BLOCK = ControlBlockPages
DEFAULT PARTITION = {DefaultPartitionNumber
NONE }
COMMENT PARTITION = {CommentPartitionNumber
DEFAULT
NONE }
MAXPARTITIONS = MaximumNumberOfPartitions
AUDIT NAME = 'AuditName'
{COMMENT
DATA
DEFINITION
STORAGE
AUTHORIZATION
SECTION
ALL }[...] AUDIT ELEMENTS ][,...] NewLogDefinition
- DBEnvironmentName
identifies the DBEnvironment in which you want to
initialize one or two new log files. Unless you specify an absolute
path name, ALLBASE/SQL assumes the name is relative to your current
working directory.
- ConnectionName
associates a user specified name with this connection. This name must
be unique for each DBEnvironment connection within an application. If a
ConnectionName is not specified,
DBEnvironmentName is the default.
ConnectionName cannot exceed 128 bytes.
- MULTI
indicates the DBEnvironment can be accessed after
log initialization in multiuser mode.
- ARCHIVE
causes ALLBASE/SQL to initialize a new log in archive mode. If you
omit this parameter, the log starts in nonarchive mode.
- DUAL
causes ALLBASE/SQL to maintain two separate logs,
preferably on different media. Keeping the log files on separate
media ensures that a media failure on one device leaves the other
log undamaged. Each log write operation is performed on both logs.
Normally, only one log is read; but if an error is encountered,
ALLBASE/SQL switches to the other log. Data integrity is maintained
provided at least one good copy of each log record is on at least
one of the logs.
- AUDIT
Identifies the DBEnvironment as one that will have
audit logging performed on it with the elements specified in the
AUDIT ELEMENTS clause. This causes ALLBASE/SQL to create audit log
records as well as normal log records in the log file so that the
database can be audited.
- DataBufferPages
specifies the number of 4096-byte data buffer pages
to be used. Data buffer pages hold index and data pages.
You can request up to 50,000 data buffer pages. The
minimum number of data buffer pages is 15. The default number is
100. The total number of data buffer pages and runtime control block
pages cannot exceed 256 Mbytes.
- LogBufferPages
specifies the number of log buffer pages to be used.
You as can request from 24 to 1024 log buffer pages, limited by
the amount of storage available. The default number of log buffer
pages is 24.
- MaxTransactions
specifies the maximum number of concurrent
transactions to be supported. You can specify a value
from 2 to 240. The default is 50. This value overrides the maximum
value stored in the DBECon file. Any attempt to start a transaction
beyond the maximum limit waits for the specified TIMEOUT and returns
an error if TIMEOUT is exceeded. For each user logged on to the
system at any one time, you should allow 2 concurrent transactions
for just being connected to the DBE.
- MAXIMUM TIMEOUT
specifies the maximum user timeout value. This value
temporarily overrides the maximum stored in the DBECon file. When
no value is specified, the DBECon file value is the default.
- DEFAULT TIMEOUT
specifies the default user timeout value. This value
temporarily overrides the maximum stored in the DBECon file. When
no value is specified, the DBECon file value is the default.
- TimeoutValue
is an integer literal greater than zero. If the
TimeoutValue is not qualified by MINUTES, SECONDS is
assumed. If representing seconds, TimeoutValue must be in
the range of 1 to 2,147,483,647. If representing minutes,
TimeoutValue must be in the range of 1 to
35,791,394.
- ControlBlockPages
specifies the number of runtime control blocks to be allocated. Any
value specified here temporarily overrides the value specified in the
DBECon file. You can specify a value from 17 to 2,000 pages for
this parameter. The default is 37 pages. The total number of data buffer
pages and runtime control block pages cannot exceed 256 Mbytes.
- DefaultPartitionNumber
Specifies the default partition number for the DBEnvironment.
DefaultPartitionNumber must be in the range 1 and 32767.
If NONE is specified, tables assigned to the DEFAULT PARTITION do not
generate audit log records. no tables in the DBEnvironment are prepared
for audit logging and no operation done on these tables is logged. See
the CREATE TABLE and ALTER TABLE statements for information
on assigning a partition for a table.
- CommentPartitionNumber
Specifies the partition number for comments made in the DBEnvironment.
CommentPartitionNumber must be a number between 1 and
32767. If no COMMENT PARTITION is specified, DEFAULT is implied.
If the comment partition is DEFAULT and the default partition number is
later changed in a START DBE NEWLOG statement (but the comment
partition is not changed from DEFAULT), the comment partition number will
also change to the new default partition number.
- MaximumNumberOfPartitions
Specifies the maximum number of partitions for the DBEnvironment.
MaximumNumberOfPartitions is required to be a number
between 1 and 831. This number indicates the number of partition
instances the DBEnvironment is expected to track.
For audit logging purposes, the number of partition instances is
calculated as the sum of the number of DATA partitions and the number of
elements (except the DATA audit element) specified in the AUDIT ELEMENTS
clause. Specifying ALL audit elements (see below) includes 6 elements,
implying that 6 partitions are used. Set this value only as high as
needed so that unnecessary space is not reserved unless you plan for more
partitions or audit elements.
- AuditName
Specifies the name of this audit DBEnvironment.
AuditName is limited to 8 bytes. This clause must be
specified if AUDIT LOG has been specified. The AuditName
appears in outputs of the Audit Tool.
- AUDIT ELEMENTS
Specifies the types of audit logging that will be done for the
database. If this clause is omitted and AUDIT LOG is specified, DATA
AUDIT ELEMENTS is implicit. The audit elements are as follow:
- COMMENT
This permits use of the LOG COMMENT statement in the
DBEnvironment. Comments are logged to the defined COMMENT PARTITION.
If this element is not chosen, the LOG COMMENT statement
returns an error.
- DATA
This is the default element. It causes audit log records to be
generated for any data operations (INSERT, UPDATE, or
DELETE) on tables that are in an audit partition of the
DBEnvironment other than NONE. (Tables can be specified to be in
partition NONE and thus not participate in the audit logging
process.)
- DEFINITION
This includes audit logging of the following statements:
CREATE TABLE
ALTER TABLE
DROP TABLE
CREATE INDEX
DROP INDEX
CREATE VIEW
DROP VIEW
CREATE RULE
DROP RULE
CREATE PROCEDURE
DROP PROCEDURE
TRANSFER OWNERSHIP
CREATE GROUP
DROP GROUP
CREATE DBEFILESET
DROP DBEFILESET
CREATE PARTITION
DROP PARTITION
TRUNCATE TABLE
- STORAGE
This includes audit logging of the following statements:
CREATE DBEFILE
DROP DBEFILE
ADD DBEFILE TO DBEFILESET
REMOVE DBEFILE FROM DBEFILESET
CREATE TEMPSPACE
DROP TEMPSPACE
- AUTHORIZATION
This includes audit logging of the following statements:
GRANT
REVOKE
ADD TO GROUP
REMOVE FROM GROUP
- SECTION
This includes audit logging of the creation and deletion of
permanent sections. Permanent sections are created when a program is
preprocessed, and are deleted by the DROP MODULE statement.
Logging of section creation does not include any SETOPT information
associated with the section. See the SETOPT statement in this
chapter.
- ALL
This is equivalent to specifying COMMENT DATA DEFINITION STORAGE
AUTHORIZATION SECTION AUDIT ELEMENTS as described above.
- NewLogDefinition
is a clause that provides ALLBASE/SQL with the information needed to
create one or more new log files. The syntax for this clause is presented
in the next section.
LOG DBEFILE DBELog1ID [AND DBELog2ID]
WITH PAGES = DBELogSize,
NAME = 'SystemFileName1' [AND 'SystemFileName2']
- LOG DBEFILE
describes the two log files if the DUAL LOG option
is specified, or a single log file otherwise.
- DBELog1ID and DBELog2ID
are the basic names identifying the log files.
- DBELogSize
specifies the number of 512-byte pages in one log
file. If dual logging is used, both logs must be the same size.
The DBE log size should be at least 250 pages and no greater than
524,287 pages. The default is 250. If you choose an odd number of
pages, the number is rounded up to an even number.
- SystemFileName1 and SystemFileName2
identify how the logs are known to the operating
system. The logs are created relative to the DBECon file directory
unless an absolute path name is specified. If a log file by the same
name already exists, use SQLUtil to purge it before issuing the
START DBE NEWLOG statement.
The usual reason for using START DBE NEWLOG is to increase
or decrease log file space or to invoke dual logging.
The logs are always created in the same group and
account as the DBEnvironment.
When you choose an odd number of log pages using the WITH PAGES
clause of the new log definition, the number is rounded
up to an even number, which is displayed in SHOWLOG.
Do not use this statement unless you are certain that the
preceding termination of ALLBASE/SQL was normal and all active
sessions terminated normally. Before using the
START DBE NEWLOG statement, it is recommended that you issue a
START DBE statement in single user mode to ensure the
DBEnvironment is in a consistent state before the existing log(s) are
disassociated from the DBEnvironment.
Use the ARCHIVE option only as a part of a static
backup procedure with archive logging. Refer to the "Backup and
Recovery" chapter in the ALLBASE/SQL Database Administration
Guide for more information. The preferred method for starting
archive logging is to use the SQLUtil STOREONLINE command
after initial loading of the DBEnvironment is complete.
No DBE sessions for the DBEnvironment can be in
effect when this statement is processed.
Timeout values set in the START DBE NEWLOG statement remain
in effect only as long as there is a DBEnvironment session connected
to the DBEnvironment, and do not modify the values stored in the
DBECon file.
If no MAXIMUM TIMEOUT limit is specified, the MAXIMUM TIMEOUT
limit stored in the DBECon file remains in effect. If no
DEFAULT TIMEOUT value is specified, the DEFAULT TIMEOUT value stored
in the DBECon file remains in effect.
If MAXIMUM TIMEOUT = NONE, infinity (no timeout) is assumed. If
DEFAULT TIMEOUT = MAXIMUM, the value of MAXIMUM TIMEOUT
is assumed. The DEFAULT TIMEOUT value may not exceed the MAXIMUM
TIMEOUT value.
The following parameters defined in the START DBE NEW
statement are stored in the DBECon file:
DBEnvironment language
User mode (single versus multi)
Number of data buffer pages
Number of log buffer pages
Maximum transactions
Maximum timeout value
Default timeout value
Number of runtime control block pages
DBEFile0 system file name
Log system file name(s)
Audit logging (chosen versus not)
Audit name
Audit elements
Default partition
Comment partition
Maximum number of partitions
You can reconfigure a DBEnvironment by using SQLUtil to alter
DBECon file parameters. All parameters except the audit information
(logging, audit elements, name, default, comment and maximum
partition), or the name of the DBECon file and DBEFile0 may be
changed. Refer to the ALLBASE/SQL Database Administration
Guide for additional information.
If AUDIT LOG is specified, the clauses AUDIT NAME, DEFAULT
PARTITION, and MAXPARTITIONS must also be specified. Further, if no
AUDIT ELEMENTS are specified, DATA is used as a default.
Use of the clause ALL AUDIT ELEMENTS implies specification
of all of the audit elements.
The usual reason for using START DBE NEWLOG is to increase
or decrease log file space, to invoke dual logging or audit logging,
or to alter audit logging parameters.
Audit parameters set in the START DBE NEWLOG statement
modify the values stored in the DBECon file.
If an audit parameter is not specified in the statement, the audit
parameter remains unchanged. The parameters AUDIT NAME, DEFAULT
PARTITION, MAXPARTITIONS, COMMENT PARTITION, and AUDIT ELEMENTS can
be changed at any time through the START DBE NEWLOG
statement.
If AUDIT LOG is not specified in this statement, the default is
that it is disabled. Thus if the DBEnvironment had audit logging
enabled and then specified a START DBE NEWLOG statement
without AUDIT LOG, audit logging would then be disabled.
Changing MAXPARTITIONS on a START DBE NEWLOG prevents roll
forward recovery through prior log files, since their structure will
differ from the new logs' structure. The same is true of going from
non-audit logs to audit logs and vice versa. Therefore, it is
recommended that an audit DBEnvironment be designed with a large
enough MAXPARTITIONS when it is created.
Additional log files should be created with the
SQLUtil ADDLOG command.
Refer to the ALLBASE/SQL Database Administration
Guide for additional information on log file
management.
You need to be the DBECreator or super-user to issue the START DBE
NEWLOG statement. hpdb must have write permission in the target
directory for the log file(s).
The DBEnvironment is restored to a consistent state. Any transactions
incomplete when the DBEnvironment was last shut down are rolled back, and work
done by completed transactions is committed.
START DBE '../sampledb/PartsDBE'
SQLUtil is used to delete the existing log files: PartsLg1 and PartsLg2.
STOP DBE
The log files are reinitialized.
START DBE '../sampledb/PartsDBE' MULTI NEWLOG DUAL LOG
LOG DBEFILE PartsDBELog1 AND PartsDBELog2
WITH PAGES = 250, NAME = 'PartsLg1' AND 'PartsLg2'
The DBEnvironment is restored to a consistent state. Any transactions
incomplete when the DBEnvironment was last shut down are rolled
back, and work done by completed transactions is committed.
START DBE '../sampledb/PartsDBE'
STOP DBE
After the DBEnvironment is stopped, the log files can be purged.
New log files are reinitialized and audit logging is enabled.
START DBE '../sampledb/PartsDBE' MULTI NEWLOG DUAL
AUDIT LOG,
AUDIT NAME = 'PrtsDBE1',
DEFAULT PARTITION = 1,
MAXPARTITIONS = 20,
DATA AUDIT ELEMENTS,
LOG DBEFILE PartsDBELog1 AND PartsDBELog2
WITH PAGES = 1000, NAME = 'PartsLg1' AND 'PartsLg2'
You must create additional log files with the SQLUtil ADDLOG command.
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