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Wednesday, June 22, 2016

Repairing Chained Rows Table using Toad

Chaining occurs when an update increase a row length such as that it cannot fit in its current data block and must migrate to a new data block that has sufficient space for entire row. The only way to correct this problem to delete those chained rows and re-insert them. Below are the steps to remove the chained row from a table:
        Copy the chained rows to the temporary table.
        Delete them from the original table.
        Insert backup them again into the original
You can perform this operation using Toad in simple and efficient way.
Open the “Repair Chained rows” Screen from the menu: Database –> Optimize –> Repair Chained Rows
 
 
 
        Click on “Add” button to add the table from different schemas that you want to analyze for possible chained rows.
        Check the ‘repair” next to he each table indicating whether or not you are including in the repair process.
        Specify the name of temporary table (optional). If you not defined the temp table name then toad with automatic defines one temp table with unique name.
        Specify the name of rollback segment to perform this operation. The size of this rollback segment depends on the number of chained rows you have to handle (as more as the chained rows larger enough the rollback segment needed).
        Finally click on the “repair” button it will eliminate all of your chained rows by displaying a dialog box of
     operation complete along with statistics and information report. 
Note: After Applying the chained row concept you must need to Analyze that particular table.