11 CTX_OUTPUT Package
This chapter provides reference information for using the CTX_OUTPUT
PL/SQL package.
CTX_OUTPUT
contains the following stored procedures:
Name | Description |
---|---|
Adds an event to the index log. |
|
Enables tracing. |
|
Turns off the gathering of query stats for the index. |
|
Enables gathering of query stats for the index. |
|
Halts logging of index and document services requests. |
|
Stops logging queries into a logfile. |
|
Returns the value of a trace. |
|
Prints traces to logfile. |
|
Returns the name of the current log file. |
|
Removes an event from the index log. |
|
Disables tracing. |
|
Clears a trace. |
|
Starts logging index and document service requests. |
|
Creates a log file of queries. |
Note:
The APIs in the CTX_OUTPUT
package do not support identifiers that are prefixed with the schema or the owner name.
11.1 ADD_EVENT
Use this procedure to add an event to the index log for a more detailed log output or to enable error tracing for Oracle Text errors. Index logs are now appended to the database trace files.
Syntax
CTX_OUTPUT.ADD_EVENT(event in NUMBER, errnum in NUMBER := null);
- event
-
Specify the type of index event to log. You can add the following events:
-
CTX_OUTPUT.EVENT_INDEX_PRINT_ROWID
, which logs the rowid of each row as it is indexed. This is useful for debugging a failed index operation. -
CTX_OUTPUT.EVENT_INDEX_PRINT_TOKEN
, which prints the each token as it is being indexed. -
CTX_OUTPUT.EVENT_DRG_DUMP_ERRORSTACK
, which prints the stack trace for the specified DRG error in the log. An error will be raised iferrnum
is not specified.
Note:
CTX_OUTPUT.EVENT_OPT_PRINT_TOKEN
, which prints each token as it is being optimized, andCTX_OUTPUT.EVENT_INDEX_PRINT_TOKEN
, which prints each token as it is being indexed, are disabled when using PDB lockdown profileCTX_PROTOCOLS
. -
- errnum
-
Specify the DRG error number for a
CTX_OUTPUT.EVENT_DRG_DUMP_ERRRORSTACK
event.
Example
begin CTX_OUTPUT.ADD_EVENT(CTX_OUTPUT.EVENT_INDEX_PRINT_ROWID); end;
Related Topics
11.2 ADD_TRACE
Use this procedure to enable a trace. If the trace has not been enabled, this call adds the trace to the list of active traces and resets its value to 0. If the trace has already been enabled, an error is raised.
Syntax
CTX_OUTPUT.ADD_TRACE(trace_id BINARY_INTEGER);
- trace_id
-
Specify the ID of the trace to enable. See Table 11-1 for possible trace values.
Notes
Table 11-1 shows the available traces:
Table 11-1 Available Traces
Symbol | ID | Metric |
---|---|---|
|
1 |
Time spent executing user datastore |
|
2 |
Time spent invoking the |
|
3 |
Time spent executing the |
|
4 |
Time spent fetching from |
|
5 |
Total number of rows whose token metadata was fetched from |
|
6 |
Time spent fetching the |
|
7 |
Time spent reading |
|
8 |
Number of rows whose |
|
9 |
Number of bytes read from |
|
10 |
Time spent fetching and reading |
|
11 |
Time spent in |
|
15 |
Time spent fetching and reading |
|
19 |
Time spent reading |
|
23 |
Time spent reading |
|
25 |
Time spent extracting a snippet from a document |
|
26 |
Time spent by document service procedures (snippet, highlight, and markup) |
Tracing is independent of logging. Logging does not have to be on to start tracing, and vice-versa.
Traces are associated with a session—they can measure operations that take place within a single session, and conversely, cannot make measurements across sessions.
During parallel sync or optimize, the trace profile will be copied to the slave sessions if and only if tracing is currently enabled. Each slave will accumulate its own traces and implicitly write all trace values to the slave logfile before termination.
Related Topics
11.3 DISABLE_QUERY_STATS
Disables gathering of query stats for the index.
Syntax
ctx_output.disable_query_stats( index_name IN VARCHAR2 );
Example
Turn off gathering of query stats for the index myindex
.
CTX_OUTPUT.DISABLE_QUERY_STATS(myindex);
Notes
Once the query stats is disabled for an index, gathering and storing query-related metadata is stopped for that index. All the entries corresponding to that index are cleared from the dictionary tables. An error is returned if you call this procedure on an index where query stats is not enabled.
11.4 ENABLE_QUERY_STATS
Enables gathering of query stats for the index. To have query-related metadata stored for the index, use this procedure to enable collection of statistics on that index. You can only access the gathered metadata when ctx_output.enable_query_stats
is turned on for the index.
Note:
Accessing the query stats metadata only works when ctx_output.enable_query_stats
is turned on for the index. Please see CTX_REPORT."INDEX_STATS" for the list of gathered query stats metadata.
Syntax
ctx_output.enable_query_stats( index_name IN VARCHAR2 );
Example
Turn on gathering of query stats for the index myindex
.
CTX_OUTPUT.ENABLE_QUERY_STATS(myindex);
Notes
The information that shows whether query stats is enabled on an index is available in the views: CTX_INDEXES
and CTX_USER_INDEXES
under the column idx_query_stats_enabled
, which is in both of these views. If query_stats
is enabled for an index, then the column displays YES; if not, then the column displays NO.
The data corresponding to the query statistics will be stored in persistent dictionary tables. Once statistics
has been enabled for a particular index, query statistics will be collected for that index from all sessions.
If you call this procedure for an index where query stats is already enabled, then an error is thrown.
Statistics collection has a minimal effect on query performance.
11.5 END_LOG
This procedure halts logging index and document service requests.
Syntax
ctx_output.end_log;
Example
begin CTX_OUTPUT.END_LOG; end;
11.6 END_QUERY_LOG
Use this procedure to stop logging queries into the database trace files.
Syntax
ctx_output.end_query_log;
Example
begin
CTX_OUTPUT.START_QUERY_LOG('mylog1'); < get queries > CTX_OUTPUT.END_QUERY_LOG;
end;
11.7 GET_TRACE_VALUE
Use this procedure to programmatically retrieve the current value of a trace.
Syntax
CTX_OUTPUT.GET_TRACE_VALUE(trace_id BINARY_INTEGER);
- trace_id
-
Specify the trace ID whose value you want. See Table 11-1 for possible values.
Example
This sets the value of the variable value:
value := ctx_output.get_trace_value(trace_id);
Notes
You can also retrieve trace values through SQL:
select * from ctx_trace_values;
See "CTX_TRACE_VALUES" for the entries in the CTX_TRACE_VALUES
view.
If the trace has not been enabled, an error is raised.
Traces are not reset to 0 by this call.
Traces are associated with a session—they can measure operations that take place within a single session, and conversely, cannot make measurements across sessions.
Related Topics
11.8 LOG_TRACES
Use this procedure to print all active traces to the RDBMS trace files.
Syntax
CTX_OUTPUT.LOG_TRACES;
Notes
Traces are not reset to 0 by this call.
The traces now go to the database trace files.
Related Topics
11.9 LOGFILENAME
Returns the current session's trace file name. An error occurs if logging is not started.
Syntax
CTX_OUTPUT.LOGFILENAME RETURN VARCHAR2;
Returns
Log file name
Example
declare logname varchar2(100); begin logname := CTX_OUTPUT.LOGFILENAME; dbms_output.put_line('The current log file is: '||logname); end;
11.10 REMOVE_EVENT
Use this procedure to remove an event added through ctx_output.add_event
.
Syntax
CTX_OUTPUT.REMOVE_EVENT(event in NUMBER);
- event
-
Specify the type of index event to remove from the log. You can remove the following events:
-
CTX_OUTPUT.EVENT_INDEX_PRINT_ROWID
, which logs the rowid of each row after it is indexed. This is useful for debugging a failed index operation. -
CTX_OUTPUT.EVENT_OPT_PRINT_TOKEN
, which prints each token as it is being optimized. -
CTX_OUTPUT.EVENT_INDEX_PRINT_TOKEN
, which prints the each token as it is being indexed.
-
Example
begin
CTX_OUTPUT.REMOVE_EVENT(CTX_OUTPUT.EVENT_INDEX_PRINT_ROWID);
end;
Related Topics
"ADD_EVENT "
11.11 REMOVE_TRACE
Use this procedure to disable a trace.
Syntax
CTX_OUTPUT.REMOVE_TRACE(trace_id BINARY_INTEGER);
- trace_id
-
Specify the ID of the trace to disable. See Table 11-1 for possible values.
Notes
If the trace has not been enabled, an error is raised.
Related Topics
11.12 RESET_TRACE
Use this procedure to clear a trace (that is, reset it to 0).
Syntax
CTX_OUTPUT.RESET_TRACE(trace_id BINARY_INTEGER);
- trace_id
-
Specify the ID of the trace to reset. See Table 11-1 for possible values.
Notes
If the trace has not been enabled, an error is raised.
Related Topics
11.13 START_LOG
Begin logging index and document service requests. Starting with Oracle Database 12c Release 2 (12.2), the index logs are written to the database trace files.
Syntax
CTX_OUTPUT.START_LOG(logfile in varchar2, overwrite in default true);
- logfile
-
Specify the name of the log file. Starting with Oracle Database 12c Release 2 (12.2), the logfile parameter is ignored. The logs are now appended to the database trace files. Use the dictionary views such as
V$DIAG_INFO
andV$PROCESS
to find the path to your current session's trace file or to the trace file for each Oracle Database process.The Automatic Diagnostic Repository Command Interpreter (ADRCI) utility can also be used to access the trace files.
- overwrite
-
Specify whether you want to overwrite or append to the original query log file specified by logfile, if it already exists. Starting with Oracle Database 12c Release 2 (12.2), this parameter is ignored. By default, all logs are appended to the database trace file.
Examples
begin CTX_OUTPUT.START_LOG('mylog1'); end;
To view the indexing logs, search for COMPONENT_NAME=’CONTEXT_INDEX’
in view V$DIAG_TRACE_FILE_CONTENTS
:
select PAYLOAD from V$DIAG_TRACE_FILE_CONTENTS where COMPONENT_NAME='CONTEXT_INDEX' and TRACE_FILENAME = trc_name;
To view the query logs, search for COMPONENT_NAME=’CONTEXT_QUERY’
in view V$DIAG_TRACE_FILE_CONTENTS
:
select PAYLOAD from V$DIAG_TRACE_FILE_CONTENTS where COMPONENT_NAME='CONTEXT_QUERY' and TRACE_FILENAME = trc_name;
Parallel Query (PQ) Slaves have trace filenames of the type: SID_
pxxx
_PID.trc
. To see the traces in the parallel slaves:
select TRACE_FILENAME, PAYLOAD from V$DIAG_TRACE_FILE_CONTENTS where COMPONENT_NAME='CONTEXT_INDEX' and TRACE_FILENAME LIKE '%p00%';
Notes
No logs are written if the PDB lockdown profile CTX_LOGGING
is enabled.
Logging does not have to be on
to start tracing, and vice-versa.
Logging is associated with a session-it can log operations that take place within a single session, and, conversely, cannot make measurements across sessions.
Filenames used in CTX_OUTPUT.START_LOG
are restricted to the following characters: alphanumeric, minus, period, space, hash, underscore, single and double quotes. Any other character in the filename will raise an error.
11.14 START_QUERY_LOG
Begin logging query requests. Starting with Oracle Database 12c Release 2 (12.2), the query logs are written to the database trace files.
Use CTX_OUTPUT.END_QUERY_LOG
to stop logging queries. Use CTX_REPORT.QUERY_LOG_SUMMARY
to obtain reports on logged queries, such as which queries returned successfully the most times.
The query log includes the query string, the index name, and the timestamp of the query, as well as whether or not the query successfully returned a hit. A successful query for the phrase Blues Guitarists made at 6:46 (local time) on November 11th, 2003, would be entered into the query log in this form:
<QuerySet><TimeStamp>18:46:51 02/04/03</TimeStamp><IndexName> IDX_SEARCH_TABLE</IndexName><Query>Blues Guitarists</Query><ReturnHit>Yes</ReturnHit></QuerySet>
Syntax
CTX_OUTPUT.START_QUERY_LOG(logfile in varchar2, overwrite in default true);
- logfile
-
Specify the name of the query log file. Starting with Oracle Database 12c Release 2 (12.2), the
logfile
parameter is ignored. The logs are appended to the database trace files instead. Use the dictionary views such asV$DIAG_INFO
andV$PROCESS
to find the path to your current session's trace file or to the trace file for each Oracle Database process.The Automatic Diagnostic Repository Command Interpreter (ADRCI) utility can also be used to access the trace files.
- overwrite
-
Specify whether you want to overwrite or append to the original query log file specified by
logfile
, if it already exists. Starting with Oracle Database 12c Release 2 (12.2), this parameter is ignored. By default, all logs are appended to the database trace file.
Example
begin
CTX_OUTPUT.START_QUERY_LOG('mylog1'); < get queries > CTX_OUTPUT.END_QUERY_LOG;
end;
Notes
No logs are written if the PDB lockdown profile CTX_LOGGING
is enabled.
Filenames used in CTX_OUTPUT.START_QUERY_LOG
are restricted to the following characters: alphanumeric, minus, period, space, hash, underscore, single and double quotes. Any other character in the filename will raise an error.
Logging is associated with a session-it can log operations that take place within a single session, and, conversely, cannot make measurements across sessions.