Re: Row migrated in new data blocks

On 17 Aug 2006 17:13:34 GMT, xhoster_at_gmail.com wrote:

>Will migrated rows effect full table scans if the rowid for the selected
>rows are needed for some reason? Does the new location of the row contain
>a pointer back to the original block it was migrated from, so that the real
>rowid can be determined solely from the new location? If not, it seems
>like the only way to get the rowid and the data at the same time is for the
>FTS to break rank when it encounters a pointer to a migrated row and go get
>the row data rather than waiting for it run across that data during the
>normal course of the scan.

The old row contains a pointer to the new one, and a block read is a block read, so the migrated row is read immediately.

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Sybrand Bakker, Senior Oracle DBA