How To Install Dbms_lock Package

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1 Introduction to Oracle Supplied PL/SQL Packages & Types. Lets you request. Lets you edit an invoker's rights package. Object Privileges: GRANT execute ON dbms_lock TO GRANT execute ON dbms_lock TO uwclass; ALLOCATE_UNIQUE: Allocates a unique lock identifier (in the.

Using DBMS_LOCK • • • • • Overview Some uses of user locks: • Providing exclusive access to a device, such as a terminal • Providing application-level enforcement of read locks • Detecting when a lock is released and cleanup after the application • Synchronizing applications and enforcing sequential processing Security Model There might be operating system-specific limits on the maximum number of total locks available. This must be considered when using locks or making this package available to other users.

How To Install Dbms_lock Package

Consider granting the EXECUTE privilege only to specific users or roles. A better alternative would be to create a cover package limiting the number of locks used and grant EXECUTE privilege to specific users. An example of a cover package is documented in the DBMS_LOCK.SQL package specification file. The abbreviations for these locks as they appear in Enterprise Manager monitors are in parentheses. Constants The DBMS_LOCK package uses the constants shown in. Table 70-1 DBMS_LOCK Constants Name Alternate Name(s) Type Value OEM Abbreviation Description NL_MODE NuL1 INTEGER 1 - - SS_MODE Sub Shared INTEGER 2 ULRS This can be used on an aggregate object to indicate that share locks are being acquired on subparts of the object. SX_MODE • Sub eXclusive • Row Exclusive Mode INTEGER 3 ULRX This can be used on an aggregate object to indicate that exclusive locks are being acquired on sub-parts of the object.

How To Install Package Files

S_MODE • Shared • Row Exclusive Mode • Intended Exclusive INTEGER 4 ULRSX - SSX_MODE • Shared Sub eXclusive • Share Row Exclusive Mode INTEGER 5 - This indicates that the entire aggregate object has a share lock, but some of the sub-parts may additionally have exclusive locks. X_MODE Exclusive INTEGER 6 ULX - These are the various lock modes (nl ->'NuLl', ss ->'Sub Shared', sx ->'Sub eXclusive', s ->'Shared', ssx ->'Shared Sub eXclusive', x ->'eXclusive'). Rules and Limits When another process holds 'held', an attempt to get 'get' does the following. Table 70-2 Lock Compatibility HELD MODE GET NL GET SS GET SX GET S GET SSX GET X NL Success Success Success Success Success Success SS Success Success Success Success Success Fail SX Success Success Success Fail Fail Fail S Success Success Fail Success Fail Fail SSX Success Success Fail Fail Fail Fail X Success Fail Fail Fail Fail Fail maxwait constant integer:= 32767; The constant maxwait waits forever. Operational Notes User locks never conflict with Oracle locks because they are identified with the prefix 'UL'. You can view these locks using the Enterprise Manager lock monitor screen or the appropriate fixed views. User locks are automatically released when a session terminates.The lock identifier is a number in the range of 0 to.

Because a reserved user lock is the same as an Oracle lock, it has all the functionality of an Oracle lock, such as deadlock detection. Be certain that any user locks used in distributed transactions are released upon COMMIT, or an undetected deadlock may occur. DBMS_LOCK is most efficient with a limit of a few hundred locks for each session. Oracle strongly recommends that you develop a standard convention for using these locks in order to avoid conflicts among procedures trying to use the same locks. For example, include your company name as part of your lock names. Table 70-3 DBMS_LOCK Package Subprograms Subprogram Description Allocates a unique lock ID to a named lock.

Auto Win Hack For Gunbound Classic. Converts a lock from one mode to another. Releases a lock. Requests a lock of a specific mode. Puts a procedure to sleep for a specific time. ALLOCATE_UNIQUE Procedure This procedure allocates a unique lock identifier (in the range of to ) given a lock name.

Lock identifiers are used to enable applications to coordinate their use of locks. This is provided because it may be easier for applications to coordinate their use of locks based on lock names rather than lock numbers. Syntax DBMS_LOCK.ALLOCATE_UNIQUE ( lockname IN VARCHAR2, lockhandle OUT VARCHAR2, expiration_secs IN INTEGER DEFAULT 864000); Parameters. Table 70-4 ALLOCATE_UNIQUE Procedure Parameters Parameter Description lockname Name of the lock for which you want to generate a unique ID. Do not use lock names beginning with ORA$; these are reserved for products supplied by Oracle. Lockhandle Returns the handle to the lock ID generated by ALLOCATE_UNIQUE. You can use this handle in subsequent calls to REQUEST, CONVERT, and RELEASE.