分类: Oracle
2005-05-19 20:08:13
The DBMS_LOGMNR
package contains procedures used to initialize the LogMiner tool and to begin and end a LogMiner session.
See Also: for information about using LogMiner and DBMS_LOGMNR_D for information on the package subprograms that extract a LogMiner dictionary and re-create LogMiner tables in alternate tablespaces |
This chapter contains the following topics:
package contains procedures used to initialize the LogMiner tool and to begin and end a LogMiner session.
See Also: for information about using LogMiner and DBMS_LOGMNR_D for information on the package subprograms that extract a LogMiner dictionary and re-create LogMiner tables in alternate tablespaces |
This chapter contains the following topics:
You must have the role, EXECUTE_CATALOG_ROLE
to use the DBMS_LOGMNR package.
Table 47-1 describes the constants for the ADD_LOGFILE
options flag in the DBMS_LOGMNR
package.
Constant | Description |
---|---|
| Implicitly calls the |
|
|
Table 47-2 describes the constants for the START_LOGMNR
options flag in the DBMS_LOGMNR
package.
Constant | Description |
---|---|
| If set, DML statements corresponding to committed transactions are returned. DML statements corresponding to a committed transaction are grouped together. Transactions are returned in their commit order. Transactions that are rolled back or in-progress are filtered out, as are internal redo records (those related to index operations, management, and so on). If this option is not set, all rows for all transactions (committed, rolled back, and in-progress) are returned in the order in which they are found in the redo logs (in order of SCN values). |
| Directs a select operation on the |
| If the LogMiner dictionary in use is a flat file or in the redo log files, LogMiner updates its internal dictionary if a DDL event occurs. This ensures that correct This option cannot be used in conjunction with the |
| Directs LogMiner to use the current online database dictionary rather than a LogMiner dictionary contained in a flat file or in the redo log files being analyzed. This option cannot be used in conjunction with the Expect to see a value of |
| If set, LogMiner expects to find a LogMiner dictionary in the redo log files that were specified. The redo log files are specified with the |
| If set, the SQL delimiter (a semicolon) is not placed at the end of reconstructed SQL statements. This is helpful for applications that open a cursor and then execute the reconstructed statements. |
| If set, the When using this option, you must be sure that supplemental logging was enabled in the source database at the appropriate level and that no duplicate rows exist in the tables of interest. LogMiner does not make any guarantee regarding the uniqueness of logical row identifiers. |
| If set, LogMiner formats the reconstructed SQL statements for ease of reading. These reconstructed SQL statements are not executable. |
| Directs LogMiner to automatically add redo log files, as needed, to find the data of interest. You only need to specify the first log to start mining, or just the starting SCN or date to indicate to LogMiner where to begin mining logs. You are not required to specify any redo log files explicitly. LogMiner automatically adds and mines the (archived and online) redo log files for the data of interest. This option requires that LogMiner is connected to the same database instance that is generating the redo log files. |
A LogMiner session begins with a call to DBMS_LOGMNR.ADD_LOGFILE
or DBMS_LOGMNR.START_LOGMNR
(the former if you plan to specify log files explicitly; the latter if you plan to use continuous mining). The session ends with a call to DBMS_LOGMNR.END_LOGMNR
. Within a LogMiner session, you can specify the redo log files to be analyzed and the SCN or time range of interest; then you can issue SQL SELECT
statements against the V$LOGMNR_CONTENTS
view to retrieve the data of interest.
Subprogram | Description |
---|---|
Adds a redo log file to the existing or newly created list of redo log files for LogMiner to process, so that if a new list is created, this marks the beginning of a LogMiner session | |
You can call this function for any row returned from the | |
Finishes a LogMiner session | |
You can call this function for any row returned from the | |
Removes a redo log file from the list of redo log files for LogMiner to process | |
Initializes the LogMiner utility and starts LogMiner (unless the session was already started with a call to |
This procedure adds a file to an existing or newly created list of log files for LogMiner to process.
DBMS_LOGMNR.ADD_LOGFILE( LogFileName IN VARCHAR2, options IN BINARY_INTEGER default ADDFILE );
Parameter | Description |
---|---|
| Specifies the name of the redo log file to add to the list of redo log files to be analyzed during this session. |
| Does one of the following:
|
V$LOGMNR_CONTENTS
view, you must make a successful call to the DBMS_LOGMNR.START_LOGMNR
procedure (within the current LogMiner session). CONTINUOUS_MINE
option, the LogMiner session must be set up with a list of redo log files to be analyzed. Use the ADD_LOGFILE
procedure to specify the list of redo log files to analyze. CONTINUOUS_MINE
option and you want to analyze more than one redo log file, you must call the ADD_LOGFILE
procedure separately for each redo log file. The redo log files do not need to be registered in any particular order. RESETLOGS
SCN
as the first redo log file. (The database RESETLOGS
SCN
uniquely identifies each execution of an ALTER
DATABASE
OPEN
RESETLOGS
statement. When the online redo logs are reset, Oracle creates a new and unique incarnation of the database.) RESETLOGS SCN
) than that with which the current list of redo log files is associated, use the END_LOGMNR
procedure to end the current LogMiner session, and then build a new list using the ADD_LOGFILE
procedure. ORA-01284
: file ORA-01287
: file ORA-01289
: cannot add duplicate log file ORA-01290
: cannot remove unlisted log file ORA-01324
: cannot add file This function is designed to be used in conjunction with the MINE_VALUE
function.
If the MINE_VALUE
function returns a NULL
value, it can mean either:
NULL
value.To distinguish between these two cases, use the COLUMN_PRESENT
function, which returns a 1
if the column is present in the redo or undo portion of the data. Otherwise, it returns a 0
.
DBMS_LOGMNR.COLUMN_PRESENT( sql_redo_undo IN RAW, column_name IN VARCHAR2 default '') RETURN NUMBER;
Parameter | Description |
---|---|
| Specifies either the |
| Specifies the fully qualified name ( |
Table 47-6 describes the return values for the COLUMN_PRESENT
function. The COLUMN_PRESENT
function returns 1 if the self-describing record (the first parameter) contains the column specified in the second parameter. This can be used to determine the meaning of NULL
values returned by the DBMS_LOGMNR.MINE_VALUE
function.
Return | Description |
---|---|
| Specified column is not present in this row of |
| Column is present in this row of |
COLUMN_PRESENT
function, you must have successfully started LogMiner. COLUMN_PRESENT
function must be invoked in the context of a select operation on the V$LOGMNR_CONTENTS
view. COLUMN_PRESENT
function does not support LONG
, LOB, ADT
, or COLLECTION
datatypes. sql_redo_undo
parameter depends on the operation performed and the data of interest: UNDO_VALUE
. REDO_VALUE
. REDO_VALUE
(because the value of a column prior to an insert operation will always be null). UNDO_VALUE
(because the value of a column after a delete operation will always be null).Currently, a LogMiner dictionary is not associated with the LogMiner session. You must specify a LogMiner dictionary for the LogMiner session.
The value specified for the column_name
parameter was not a fully qualified column name.
This procedure finishes a LogMiner session. Because this procedure performs cleanup operations that may not otherwise be done, you must use it to properly end a LogMiner session. This procedure is called automatically when you log out of a database session or when you call DBMS_LOGMNR.ADD_LOGFILE
and specify the NEW
option.
DBMS_LOGMNR.END_LOGMNR;
The END_LOGMNR
procedure was called without adding any log files or before the START_LOGMNR
procedure was called.
This function facilitates queries based on a column's data value. This function takes two arguments. The first one specifies whether to mine the redo (REDO_VALUE
) or undo (UNDO_VALUE
) portion of the data. The second argument is a string that specifies the fully qualified name of the column to be mined. The MINE_VALUE
function always returns a string that can be converted back to the original datatype.
DBMS_LOGMNR.MINE_VALUE( sql_redo_undo IN RAW, column_name IN VARCHAR2 default '') RETURN VARCHAR2;
Parameter | Description |
---|---|
| Specifies either the |
| Specifies the fully qualified name ( |
Return | Description |
---|---|
| The column is not contained within the self-describing record, or the column value is |
| The column is contained within the self-describing record; the value is returned in string format. |
MINE_VALUE
function, you must have successfully started LogMiner. MINE_VALUE
function must be invoked in the context of a select operation from the V$LOGMNR_CONTENTS
view. MINE_VALUE
function does not support LONG
, LOB, ADT
, or COLLECTION
datatypes. sql_redo_undo
parameter depends on the operation performed and the data of interest: UNDO_VALUE
. REDO_VALUE
. REDO_VALUE
(because the value of a column prior to an insert operation will always be null). UNDO_VALUE
(because the value of a column after a delete operation will always be null).Currently, a LogMiner dictionary is not associated with the LogMiner session. You must specify a LogMiner dictionary for the LogMiner session.
The value specified for the column_name
parameter was not a fully qualified column name.
This procedure removes a redo log file from an existing list of redo log files for LogMiner to process.
Note: This procedure replaces the |
DBMS_LOGMNR.REMOVE_LOGFILE( LogFileName IN VARCHAR2);
Parameter | Description |
---|---|
| Specifies the name of the redo log file to be removed from the list of redo log files to be analyzed during this session. |
V$LOGMNR_CONTENTS
view, you must make a successful call to to the DBMS_LOGMNR.START_LOGMNR
procedure (within the current LogMiner session). END_LOGMNR
procedure to end the current LogMiner session, and then build a new list using the ADD_LOGFILE
procedure. ADD_LOGFILE
procedure must match the database ID and RESETLOGS
SCN
of the removed redo log files. Therefore, to analyze the redo log files from a different database (or a database incarnation with a different database RESETLOGS
SCN
) than that with which the current list of redo log files is associated, use the END_LOGMNR
procedure to end the current LogMiner session, and then build a new list using the ADD_LOGFILE
procedure.This procedure starts LogMiner by loading the dictionary that LogMiner will use to translate internal schema object identifiers to names.
DBMS_LOGMNR.START_LOGMNR( startScn IN NUMBER default 0, endScn IN NUMBER default 0, startTime IN DATE default '01-jan-1988', endTime IN DATE default '31-dec-2110', DictFileName IN VARCHAR2 default '', Options IN BINARY_INTEGER default 0 );
Parameter | Description |
---|---|
| Directs LogMiner to return only redo records with an SCN greater than or equal to the |
| Directs LogMiner to return only redo records with an SCN less than or equal to the |
| Directs LogMiner to return only redo records with a timestamp greater than or equal to the This parameter is ignored if |
| Directs LogMiner to return only redo records with a timestamp less than or equal to the This parameter is ignored if |
| Specifies the flat file that contains the LogMiner dictionary. It is used to reconstruct You need to specify this parameter only if neither |
|
START_LOGMNR
procedure, you can query the following views: V$LOGMNR_CONTENTS
- contains history of information in redo log files V$LOGMNR_DICTIONARY
- contains current information about the LogMiner dictionary file extracted to a flat file V$LOGMNR_PARAMETERS
- contains information about the LogMiner session(You can query the V$LOGMNR_LOGS
view after a redo log file list has been added to the list of files that LogMiner is to mine.)
DBMS_LOGMNR.START_LOGMNR
. You must specify all desired parameters and options (including SCN and time ranges) each time you call DBMS_LOGMNR.START_LOGMNR
CONTINUOUS_MINE
option directs LogMiner to automatically add redo log files, as needed, to find the data of interest. You need to specify only the first log to start mining, or just the starting SCN or date to indicate to LogMiner where to begin mining logs. Keep the following in mind when using the CONTINUOUS_MINE
option: V$ARCHIVED_LOGS
view to determine which redo log file entries will be found by LogMiner. Even if an entry is listed in the database control file (and the V$ARCHIVED_LOGS
view), the archived redo log file may not be accessible by LogMiner for various reasons. For example, the archived redo log file may have been deleted or moved from its location (maybe because of a backup operation to tape), or the directory where it resides may not be not available.
CONTINUOUS_MINE
option and an ending time or SCN that will occur in the future (or you do not specify an end time or SCN), a query of the V$LOGMNR_CONTENTS
view will not finish until the database has generated redo log files beyond the specified time or SCN. In this scenario, LogMiner will automatically add archived redo log files to the LogMiner redo log file list as they are generated. In addition, in this scenario only, LogMiner may automatically remove redo log files from the list to keep it at 50 processed redo files. This is to save PGA memory as LogMiner automatically adds redo log files to the list. If LogMiner did not perform automated removal, memory could eventually be exhausted. CONTINUOUS_MINE
option is not specified, it is possible that the database is writing to the online redo log file at the same time that LogMiner is reading the online redo log file. If a log switch occurs while LogMiner is reading an online redo log file, the database will overwrite what LogMiner is attempting to read. The data that LogMiner returns if the file it is trying to read gets overwritten by the database is unpredictable.startTime
nor a startScn
parameter, LogMiner will set the startScn
parameter to use the lowest SCN value from the redo log file that contains the oldest changes. DBMS_LOGMNR.START_LOGMNR
without the CONTINUOUS_MINE
option, and you specify: 0
for the startTime
or startScn
value, then the lowest SCN in the LogMiner redo log file list will be used as the startScn
startTime
or startScn
value, then an error is returned 0
or a nonzero number for the endTime
or endScn
value, then the highest SCN in the LogMiner redo log file list will be used as the endScn
DBMS_LOGMNR.START_LOGMNR
with the CONTINUOUS_MINE
option, and you specify: 0
for the startTime
or startScn
value, then an error is returned. startTime
or startScn
value that is greater than any value in the database's archived redo log files, then LogMiner starts mining in the online redo log file. LogMiner will continue to process the online redo log file until it finds a change at, or beyond, the requested starting point before it returns rows from the V$LOGMNR_CONTENTS
view. endTime
or endScn
parameter value that indicates a time or SCN in the future, then LogMiner includes the online redo log files when it mines. When you query the V$LOGMNR_CONTENTS
view, rows will be returned from this view as changes are made to the database, and will not stop until LogMiner sees a change beyond the requested ending point. 0
for the endTime
or endScn
parameter value, then LogMiner includes the online redo log files when it mines. When you query the V$LOGMNR_CONTENTS
view, rows will be returned from this view as changes are made to the database, and will not stop until you enter CTL+C or you terminate the PL/SQL cursor.ORA-01280
: fatal LogMiner error. The procedure fails with this exception if LogMiner encounters an internal error.
ORA-01281
: SCN range specified is invalid. The startScn
or endScn
parameter value is not a valid SCN, or endScn
is less than startScn
.
ORA-01282
: date range specified is invalid. The value for the startTime
parameter was greater than the value specified for the endTime
parameter, or there was no redo log file that was compatible with the date range specified with the startTime
and endTime
parameters.
ORA-01283
: options parameter specified is invalid. ORA-01284
: file The LogMiner dictionary file specified in the DictFileName
parameter has a full path length greater than 256 characters, or the file cannot be opened.
ORA-01285
: error reading file ORA-01291
: missing log file. <