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Stimulsoft truncate rows1/12/2024 ![]() In most implementations, a DELETE statement can return to the client the rows that were deleted.Į.g. Truncate resets the sequence for IDENTITY column types, delete does not. ![]() Truncate cannot be issued over a database link. Hence disabling table locks is a way of preventing truncate operations on a table. Truncate requires an exclusive table lock, delete requires a shared table lock. Treatment with delete depends on the configuration of the foreign keys. Delete does not.Ī truncate cannot be applied when an enabled foreign key references the table. Truncate generates a negligible amount of each.Ī truncate operation renders unusable indexes usable again. ![]() However, from 11gR2 the FLASHBACK ARCHIVE feature allows this, except in Express Editionĭelete can be granted on a table to another user or role, but truncate cannot be without using a DROP ANY TABLE grant.ĭelete generates a small amount of redo and a large amount of undo. (May be Oracle specific)ĭelete does not affect the data object id, but truncate assigns a new data object id unless there has never been an insert against the table since its creation Even a single insert that is rolled back will cause a new data object id to be assigned upon truncation.įlashback works across deletes, but a truncate prevents flashback to states prior to the operation. Truncate applies only to tables or the entire cluster. When a table is partitioned, the individual partitions can be truncated in isolation, thus a partial removal of all the table's data is possible.ĭelete can be applied to tables and tables inside a cluster. The high water mark is reset.ĭelete can be used to remove all rows or only a subset of rows. If you use the REUSE STORAGE clause then the data segments are not de-allocated, which can be marginally more efficient if the table is to be reloaded with data. Truncate can therefore not be rolled back, and a failure in the truncate process will have issued a commit anyway.ĭelete does not recover space, Truncate recovers space Various system-specific issues have to be considered, as detailed below.ĭelete is DML, Truncate is DDL ( What is DDL and DML?)īecause a TRUNCATE is DDL it involves two commits, one before and one after the statement execution. If you want to quickly delete all of the rows from a table, and you're really sure that you want to do it, and you do not have foreign keys against the tables, then a TRUNCATE is probably going to be faster than a DELETE. ![]() Differences that are common to most vendors can go directly below the headings, with differences highlighted below. I've highlighted Oracle-specific features, and hopefully the community can add in other vendors' specific difference also. ![]()
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