Tuesday, June 14, 2011

CPU Used for Table Sequential read Wait

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Statement 's I/O may indicate a Table Sequential read operation (often ROWID access) on the table specified in the Object column.
CPU Used for Table Sequential read

Description
What to do next
Perform one of the following options:
n   Click the Locate icon to find the relevant step in the execution plan.
n   Select the findings type to investigate the objects used and their structure in the Objects tab.
n   Select the Activity workspace, locate the statement associated with objects, and drill to the table consumption for the statement in the Activity workspace.
Advice
To reduce the CPU consumption for the table, consider the following solutions:
n   Change the index structure by adding a better filtering column, or change the column sequence to improve the matching and screening performed in the index tree.
n   Add columns to the index to enable index only access.
n   Switch to a full table scan.
n   Partition the table or the index.
n   Create a cluster with just one table in it and a cluster key used as the index key.
Findings refer to the whole statement - not to a specific execution plan. If a step does not exist in the selected execution plan (unless this is the result of an index overhead), switch to another plan and locate the relevant step.


    

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