In my opinion it all depends on idexes you have. If when doing a select/update you are using a where clause on an indexed column then it will be fast, but if you use a where clause on an unindexed column then it will be slower. Please note that if column being updated is indexed then it will be a bit slower since that index will need to be recaculated.
On the other hand if you make an insert in a table that has no indexes then it will be fast as records are simply added. But if you make an insert in a table that has one or mores indexes then these indexes must be updated with each row inserted and hence will become slower. Deletes is a bit of a compromise. When deleting using a where clause on a column that is indexed then it will be fast to located row/s, but after delete index will need to be recalculated. As a simply general rule it is best to have a lot of indexes when you have a lot or selects and updates(on non-indexed columns example data warehouse), but indexes must be kept to a minimum when you have a lot of inserts and fewer selects/updates. James. On Jan 2, 4:46 am, Venu Yanamandra <yanamandra.v...@gmail.com> wrote: > I also thought about it once again and think I might be wrong about the redo > information. 'coz they all fall under DML, there should be redo recorded. > But, somehow insert must be cheaper as there is no where clause to be > validated when we consider the worst case scenario. i.e., delete can have > where clause, while insert does not. > > On Fri, Jan 1, 2010 at 9:41 PM, Venu Yanamandra > <yanamandra.v...@gmail.com>wrote: > > > > > i think insert is cheaper than delete/update. > > with insert, only the constraints are validated. > > with delete, the records are searched, redo information is recorded, > > etc. > > with update, the records are searched, redo information is recorded, > > the constraints are validated again, etc. > > > -Venu > > > On Nov 26 2009, 8:47 am, Niraj Singh The King > > <parihar.nirajsi...@gmail.com> wrote: > > > As per my knowledge goes insert are less expensive as while doing update > > and > > > delete it needs to search for the records while inserting it dont needs > > > until there are some constraints but still they are less expensive > > > -- > > > Thanks and Regards, > > > Opus Software Solution(Pune) > > > Niraj Singh Parihar > > > Mobile Number : +919890492566. > > > > On Thu, Nov 26, 2009 at 8:57 AM, Javier Montani <jmont...@gmail.com> > > wrote: > > > > It also depends on how many records and indexes the table has. With too > > > > many records an update of a column that doesn't belong to an index > > could be > > > > faster than an insert which has to update all the indexes. > > > > > 2009/11/25 Andrej Hopko <ado.ho...@gmail.com> > > > > > Hi, > > > >> my standard knowledge is that inserts are cheap for database to > > > >> run, but deleting and updating are expensive operations (if this you > > > >> meant by fat operation) > > > > >> difference is mainly due to usage of indexes and locks (thats my > > > >> opinion) > > > > >> hoppo > > > > >> On 25.11.2009 23:16, noam gariani wrote: > > > >> > Do you know what is fater? > > > >> > To do update for a record , or insert a record to a db? > > > > >> -- > > > >> You received this message because you are subscribed to the Google > > > >> Groups "Oracle PL/SQL" group. > > > >> To post to this group, send email to Oracle-PLSQL@googlegroups.com > > > >> To unsubscribe from this group, send email to > > > >> oracle-plsql-unsubscr...@googlegroups.com > > > >> For more options, visit this group at > > > >>http://groups.google.com/group/Oracle-PLSQL?hl=en > > > > > -- > > > > You received this message because you are subscribed to the Google > > > > Groups "Oracle PL/SQL" group. > > > > To post to this group, send email to Oracle-PLSQL@googlegroups.com > > > > To unsubscribe from this group, send email to > > > > oracle-plsql-unsubscr...@googlegroups.com > > > > For more options, visit this group at > > > >http://groups.google.com/group/Oracle-PLSQL?hl=en-Hide quoted text - > > > > - Show quoted text - > > > -- > > You received this message because you are subscribed to the Google > > Groups "Oracle PL/SQL" group. > > To post to this group, send email to Oracle-PLSQL@googlegroups.com > > To unsubscribe from this group, send email to > > oracle-plsql-unsubscr...@googlegroups.com > > For more options, visit this group at > >http://groups.google.com/group/Oracle-PLSQL?hl=en- Hide quoted text - > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "Oracle PL/SQL" group. To post to this group, send email to Oracle-PLSQL@googlegroups.com To unsubscribe from this group, send email to oracle-plsql-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/Oracle-PLSQL?hl=en
