With this one, I set out to demonstrate the advantages of PARALLEL DML, didn't find what I thought I would, and ended up testing 8 different techniques to find out how they differed. The methods covered include both PL/SQL and SQL approaches. ), how I might cluster rows together that are subject to updates, and what I might do if I just get too many updates to handle. The fastest way to update every row in the table is to rebuild the table from scratch. Case 2 is common in Data Warehouses and overnight batch jobs.
For that, the database must remove the old entry and add the new one at the new location.
DECLARE CURSOR c1 IS SELECT * FROM test6; rec_cur c1%rowtype; BEGIN OPEN c1; LOOP FETCH c1 INTO rec_cur; EXIT WHEN c1%notfound; UPDATE test SET fk = rec_, fill = rec_WHERE pk = rec_cur.pk; END LOOP; CLOSE C1; END; / This is the simplest PL/SQL method and very common in hand-coded PL/SQL applications.
String update Table SQL = "UPDATE DBUSER SET USERNAME = ?
For example, when posting a new record to an Oracle table, where ID field is filled by a trigger from a sequence, and IMAGE is of BLOB type, Fire DAC will generate the following SQL command: Fire DAC will use the main (first) table in the SELECT ... The default value up Where Key Only uses in the WHERE phrase only the unique identifying columns and provides an efficient and safe way to locate the updating row.
When no unique identifying columns are specified and no row identifying column is found, Fire DAC will switch Update Options. Setting to False will include all fields, wihch helps to reuse the same generated statement for posting all updates and minimize DBMS work to prepare the statements.