Oracle | DBMS_HCS

Oracle DBMS_HCS_LOG Version 26ai

General Information

Library Note

Morgan's Library Page Header

The best Oracle News for FY2026

Oracle Database 26ai will be available on generic Linux platforms in January and soon on AIX and Windows

Purpose Utility functions for HCS Logging from PL/SQL code

AUTHID CURRENT_USER

Constants

Name	Data Type	Value
Logging
HCSLOG_VRB_NONE	INT	0
HCSLOG_VRB_SUMMARY	INT	1
HCSLOG_VRB_DETAIL_ALLOCS	INT	2
HCSLOG_VRB_DETAIL	INt	3

Dependencies

DBMS_ASSERT	DBMS_HIERARCHY	PLITBLM
DBMS_AVTUNE_UTIL	DBMS_MX_ODBO	UTL_FILE
DBMS_HCS_LIB	DBMS_STANDARD

Documented No

Exceptions

Error Code	Reason
ORA-20000	Log called before Log START
ORA-44003	INVALID_SQL_NAME

First Available 21c

Security Model Owned by SYS with EXECUTE granted to the DBA, PDB_DBA and AVTUNE_PKG_ROLE roles

Source {ORACLE_HOME}/rdbms/admin/dbmshcslog.sql

Subprograms

CLEAR_LOGS	HCS_CALL_CTX_CLEAR_CLOB	HCS_CALL_CTX_LOG_END
CREATE_VIEWS	HCS_CALL_CTX_GET_LOG_VRB	HCS_CALL_CTX_LOG_START
DROP_VIEWS	HCS_CALL_CTX_LOG	PURGE
HCS_CALL_CTX_BUILD_CLOB	HCS_CALL_CTX_LOG_CLEAR_CLOB	SET_LOGGING_LEVEL

CLEAR_LOGS

Clear the instance's logs dbms_hcs_log.clear_logs;

exec dbms_hcs_log.clear_logs;

      

      PL/SQL procedure successfully completed.

CREATE_VIEWS

Creates objects and views used for logging dbms_hcs_log.create_views( user IN VARCHAR2 DEFAULT SYS_CONTEXT('USERENV', 'CURRENT_SCHEMA'));

exec dbms_hcs_log.create_views;

      

      PL/SQL procedure successfully completed.

      

      SELECT object_name

      FROM dba_objects

      WHERE object_type = 'VIEW'

      and owner = USER

      AND last_ddl_time > SYSDATE-1/24

      ORDER BY 1;

      

      OBJECT_NAME

      --------------------------------

      TKHCS_LOG_BASE_VIEW

      TKHCS_LOG_CALLS

      TKHCS_LOG_CURRSESS_LASTLOG_VIEW

      TKHCS_LOG_CURRSESS_VIEW

      TKHCS_LOG_LASTSESS_VIEW

      TKHCS_LOG_VIEW

DROP_VIEWS

Drops objects and views used for logging dbms_hcs_log.drop_views( user IN VARCHAR2 DEFAULT SYS_CONTEXT('USERENV', 'CURRENT_SCHEMA'));

exec dbms_hcs_log.drop_views;

HCS_CALL_CTX_BUILD_CLOB

Builds a package private clob over numerous functions used for building a CLOB to log in one call dbms_hcs_log.hcs_call_ctx_build_clob(line IN VARCHAR2);

exec dbms_hcs_log.hcs_call_ctx_build_clob('TEST');

      

      PL/SQL procedure successfully completed.

HCS_CALL_CTX_CLEAR_CLOB

Clears the private CLOB dbms_hcs_log.hcs_call_ctx_clear_clob;

exec dbms_hcs_log.hcs_call_ctx_clear_clob;

      

      PL/SQL procedure successfully completed.

HCS_CALL_CTX_GET_LOG_VRB

Returns the logging detail level (0 - 3) dbms_hcs_log.hcs_call_ctx_get_log_vrb RETURN NUMBER;

SELECT dbms_hcs_log.hcs_call_ctx_get_log_vrb;

      

      HCS_CALL_CTX_GET_LOG_VRB

      ------------------------

                             1

HCS_CALL_CTX_LOG

Sets CALL context for subsequent call_ctx_log dbms_hcs_log.hcs_call_ctx_log(callStr IN VARCHAR2);

TBD

HCS_CALL_CTX_LOG_CLEAR_CLOB

writes the CLOB to the log and reinitializes it dbms_hcs_log.hcs_call_ctx_log_clear_clob(p_comp IN VARCHAR2);

exec dbms_hcs_log.hcs_call_ctx_log_clear_clob('TEST');

          
      *

      ORA-20000: Log called before Log START

      

      See HCS_CALL_CTX_LOG_START Demo Below

HCS_CALL_CTX_LOG_END

Logs END call and nulls out current call context dbms_hcs_log.hcs_call_ctx_log_end;

See HCS_CALL_CTX_LOG_START Demo Below

HCS_CALL_CTX_LOG_START

Sets the CALL context for subsequent call_ctx_log dbms_hcs_log.hcs_call_ctx_log_start(callStr IN VARCHAR2);

exec dbms_hcs_log.hcs_call_ctx_log_start('TEST');

      

      PL/SQL procedure successfully completed.

      

      exec dbms_hcs_log.hcs_call_ctx_log_clear_clob('TEST');

      

      PL/SQL procedure successfully completed.

      

      exec dbms_hcs_log.hcs_call_ctx_log_end;

      

      PL/SQL procedure successfully completed.

PURGE

Purges HCS logs to the given max_segments. If call_only is TRUE (default) then the value for max_segments is not used for subsequent logging. If call_only is FALSE, the value is used for subsequent logging. dbms_hcs_log.purge( max_segments IN NUMBER, call_only IN BOOLEAN DEFAULT TRUE);

exec dbms_hcs_log.purge(1, TRUE);

      

      PL/SQL procedure successfully completed.

SET_LOGGING_LEVEL (new 23ai)

Sets the analytic view log verbosity detail level dbms_hcs_log.set_logging_level( logging_level IN INT DEFAULT NULL, alter_session IN BOOLEAN DEFAULT TRUE);

exec dbms_hcs_log.set_logging_level(1, TRUE);

      

      PL/SQL procedure successfully completed.