Oracle: why parallel delete doesn't go parallel?
25,082
try
ALTER SESSION ENABLE PARALLEL DML;
DELETE /*+ parallel(table, 20) */
FROM table
WHERE flag!= 'N';
you can also try another option to delete data, using CTAS, reference from asktom Deleting many rows from a big table
create table new_table unrecoverable as select * from old_table where ....;
drop table old_table;
rename new_table to old_table;
create index old_table_idx1 on old_table(c1,c2) unrecoverable parallel 5;
Author by
Revious
Updated on October 18, 2020Comments
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Revious over 3 years
I've tried the following statement. But it doesn't proceed parallel. Why? How can I speed up the operation?
ALTER SESSION ENABLE PARALLEL DML; DELETE /*+ parallel(20) */ FROM table WHERE flag != 'N';