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Unformatted text preview: Flash back query…. Good afternoon madam and dear colleagues.. I am now going to put forward a presentation on the types of flashback queries. As the name suggests,  Flashback Query is Querying Data at a point in Time Now if we have to query the database for any past information, then we need to provide information about that past. What flashback query does is that it allows us to specify e ither the time at which the data is required or a system change number (SCN). Alongside these two, we also need to specify the query using the committed data from the corresponding time. Hence we can Refer to a point in time using a DATE value, or record system change numbers. The information we specifying for the flashback makes us classify flashback queries into 2 types time based flashback queries SCN based flashback queries For both types of flashback queries we should see to it that the DBA should In particular Set the UNDO_RETENTION initialization parameter to a value that represents how far in the past you might want to query. This is cos accordingly we can query the records for any past detail only till a certain limit. time based flashback queries in time based flashback queries , we have to actually specify the date n time at which point we need the data to be collected. To enable the flashback query mode we have to type the command,...
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This note was uploaded on 07/15/2011 for the course ECO 2023 taught by Professor Mr.raza during the Summer '10 term at FAU.
- Summer '10