Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Bulk update with commit in oracle Ask Question. Asked 4 years, 10 months ago. Active 1 year, 7 months ago. Viewed 22k times. Improve this question. OldProgrammer Thej Thej 2 2 gold badges 5 5 silver badges 17 17 bronze badges.
Why do you think you need to do a commit every 5K? Also see here asktom. If any exceptions comes, then I don't need to proceed with the records already updated — Thej. And how do you know that a record was updated? Please read the links I posted, on why frequent commits are a bad practice.
This article is an update of one written for Oracle 8i Bulk Binds which includes new features available in Oracle 9i Release 2 and beyond. There is an overhead associated with each context switch between the two engines. In Oracle8i a collection must be defined for every column bound to the DML which can make the code rather long winded. Oracle9i allows us to use Record structures during bulk operations so long as we don't reference individual columns of the collection. This restriction means that updates and deletes which have to reference inividual columns of the collection in the where clause are still restricted to the collection-per-column approach used in Oracle8i.
Bulk binds can improve the performance when loading collections from a queries. To test this create the following table. The following code compares the time taken to populate a collection manually and using a bulk bind. The select list must match the collections record definition exactly for this to be successful.
Remember that collections are held in memory, so doing a bulk collect from a large query could cause a considerable performance problem. In actual fact you would rarely do a straight bulk collect in this manner.
Instead you would limit the rows returned using the LIMIT clause and move through the data processing smaller chunks. This gives you the benefits of bulk binds, without hogging all the server memory. The following code shows how to chunk through the data in a large table. The main difference is the update statement requires a WHERE clause that references the tables ID column allowing individual rows to be targeted.
If the bulk operation was altered to reference the ID column within the collection, the following compilation error would be produced. In this example, the bulk operation is approximately twice the speed of the conventional update. Notice that a separate collection is defined for each column referenced in the bind operation. Once again it is apparent that the bulk operation is the more efficient of the two. The following section compares the performance of conventional operations with bulk delete operations.
The bulk delete operation is the same regardless of server version. The script contains rollback statements, which are necessary to make sure the bulk operation has something to delete.
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