The following table shows some of the common table access paths you may encounter while using the Explain SQL window.
| Operation | Option | Description |
|---|---|---|
|
TABLE ACCESS |
FULL |
The well-known full table scan. This involves reading every row in the table (that is, every block up to the high water mark). |
|
TABLE ACCESS |
CLUSTER |
Access of data via an index cluster key. |
|
TABLE ACCESS |
HASH |
Using a hash key to access one or more rows in a table with a matching hash value. |
|
TABLE ACCESS |
BY ROWID |
Access a single row in a table by specifying its ROWID. ROWID access is the fastest way to access a single row. Often the ROWID is obtained by an associated index lookup. |
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