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Insert Large Numbers of Rows into a Database Table with PL/SQL

Insert Large Numbers of Rows into a Database Table with PL/SQL

Everybody knows that it takes a long time to insert a large number of records into a table. To improve the speed of insertion, you can use the PL/SWL loop FORALL.

In PL/SQL, use a cursor to fetch the rows from one table and insert them into the other table.

To reduce fetching time, do a BULK COLLECT INTO:

FETCHBULK COLLECT INTOLIMIT 

To insert the fetched row, use the FORALL loop.

FORALL INDX IN .. SAVE EXCEPTIONS

You can also handle Exceptions by using the SAVE EXCEPTIONS option in the FORALL loop. Here, the FORALL loop acts as a bulk insert. When it encounters an exception, it just saves it and continues with the next record.

To view the exceptions that occurred during the insert, include the following statement after the FORALL loop:

EXCEPTIONWHEN bulk_errors THENFOR indx IN 1 .. SQL%BULK_EXCEPTIONS.COUNTLOOPerrno := SQL%BULK_EXCEPTIONS(indx).ERROR_INDEX;errmsg := SQLERRM(-1 * SQL%BULK_EXCEPTIONS(indx).ERROR_CODE);END LOOP;END;

Placing the keyword SAVE EXCEPTIONS in the FORALL loop stores all the encountered exceptions in BULK_EXCEPTIONS. Thus, the FORALL loop can be used for Bulk Insert and even Exceptions can be handled in that.

NOTE: The keyword SAVE EXCEPTIONS in the FORALL loop works only in Oracle9i.

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