ASP.NET Web PDF Document Viewer/Editor Control Library

The ROLE_TAB_PRIVS view lists roles and their corresponding table privileges. Here s the structure of the ROLE_TAB_PRIVS view: SQL> DESC ROLE_TAB_PRIVS Name Null Type -------------------------------------ROLE NOT NULL VARCHAR2(30) OWNER NOT NULL VARCHAR2(30) TABLE_NAME NOT NULL VARCHAR2(30) COLUMN_NAME VARCHAR2(30) PRIVILEGE NOT NULL VARCHAR2(40) GRANTABLE VARCHAR2(3) SQL> You can find out the specific table privileges of a user by issuing the query shown in Listing 23-8. Listing 23-8. Querying the ROLE_TAB_PRIVS View SQL> SELECT table_name, privilege 2 FROM ROLE_TAB_PRIVS 3* WHERE role='HR_SELECT'; TABLE_NAME -----------------------------JOBS REGIONS COUNTRIES EMPLOYEES LOCATIONS DEPARTMENTS JOB_HISTORY 7 rows selected. SQL> PRIVILEGE --------SELECT SELECT SELECT SELECT SELECT SELECT SELECT

2d barcode font for excel, barcode font for excel 2016, how to print barcode in excel 2007, barcode font in excel 2003, excel barcode font add in, active barcode in excel 2010, excel barcode schriftart, microsoft excel barcode generator, excel 2007 barcode generator free, excel barcode add-in 2007,

A simultaneous DDL table lock is held for operations that include the INSERT, UPDATE, DELETE, and the SELECT FOR UPDATE DML operations. DML operations need DDL table locks to ensure that some other transaction isn t changing the table definition while modifying data. This means that a table can t be altered or dropped while an uncommitted transaction is still holding a table lock on the table. Table locks can range from being very restrictive to minimally restrictive. Oracle acquires a row exclusive table lock, which indicates that a transaction holding the lock has updated one or more rows in the table. Other transactions are allowed to select, insert, update, delete, or lock rows in the same table concurrently. However, other transactions can t lock the table exclusively for their own reads or writes. All INSERT, UPDATE, and DELETE statements impose row exclusive locks. Table 6-2 summarizes the row-level and table-level DML locks that are acquired for the most common database operations. Table 6-2. DML Row- and Table-Level Locks Held for Common Operations

public ref class FileDumper { FileStream fs; StreamReader sr; DisposedFlag disposedFlag; public: FileDumper(String^ name) : fs(name, FileMode::Open), sr(%fs), disposedFlag("FileDumper") {} void Dump() { disposedFlag.EnsureObjectIsNotDisposed(); Console::WriteLine(sr.ReadToEnd()); } void CheckDisposed() { if (disposedFlag) Console::WriteLine("FileDumper is disposed"); else Console::WriteLine("FileDumper is not disposed"); } }; In this code, the managed class DisposedFlag wraps a simple Boolean variable. In its constructor, this variable is set to false, and the DisposedFlag destructor sets it to true. Since DisposedFlag is used to define an implicitly dereferenced variable in FileDumper, the DisposedFlag constructor is implicitly called by the FileDumper constructor, and the DisposedFlag destructor is implicitly called by the FileDumper destructor. To throw an ObjectDisposedException if a call is made after the FileDumper is disposed, Dump simply calls EnsureObjectIsNotDisposed on the implicitly dereferenced DisposedFlag field. EnsureObjectIsNotDisposed simply throws an exception if the wrapped Boolean variable is set to true in the DisposedFlag destructor.

Here s a brief summary of how Oracle s transactions most commonly use the Oracle locking features: The transaction that contains a DML statement acquires exclusive row locks on the rows modified by a statement within the transaction. Until this transaction commits or rolls back, other transactions can t update or delete these rows. A query in a transaction can see only committed changes made by earlier statements in the same transaction, but won t be able to see data committed by other transactions after it started. In addition to the exclusive row locks, a transaction that contains a DML statement acquires at least a row exclusive table lock on the table that contains the rows. If it s already holding a more restrictive table-level DML lock, it retains the more restrictive lock. Oracle offers other kinds of table locks besides the row exclusive lock described previously, but they are not important for our purposes here. All you need to understand is that Oracle uses rowlevel locking for updates, inserts, and deletes, and that it also automatically imposes a row exclusive table lock during these operations.

As you ve seen, Oracle automatically places DML locks on tables that are in the process of having some of their rows modified by a transaction. In addition, such a transaction simultaneously holds a table-level DDL lock on the table, which will prevent other transactions from altering or dropping the table while its DML transactions aren t yet completed. You can also place DDL locks on tables when you are conducting a purely DDL operation, without any accompanying DML transaction.

{ :0 b | /usr/local/bin/getthisfile }