Re: cursors and transactions

Hi Igor,

            A select for update will lock the rows that have been selected, thus

            preventing another transaction of updating or deleting these rows. Nothing

            is logged. What is logged are the changes made.

            No a commit or rollback doesn't anything if a transaction hasn't occured

            before.

            CIAO Pierre

Igor Sereda wrote in message <35646CCC.69119DA4_at_spb.runnet.ru>...
>Hello,
>
>Please someone could tell me this - Do opening a cursor start a
>transaction?
>What if cursor is select for update?
>
>The problem is that i need to run periodically a pl/sql procedure which
>opens a cursor for update and searches through a certain table.
>It MAY or MAY NOT actually update the table row (where current of ...).
>I cannot integrate the condition into cursor's select statement.
>When database is inactive (no operations from applications),
>these procedures do nothing, but if select for update will produce a
>transaction, it will be archived and there will be spare archived
>redo logs. So the answer seems to be crucial.
>
>Thanks to anyone, any comments are welcome,
>Igor
>
>PS.
>BTW, Will a single COMMIT or ROLLBACK statement without any
>preceding DML or something generate redo log entries?
>
>--
>Igor Sereda,
>ITC, Russia
Received on Thu May 21 1998 - 00:00:00 CDT