Difference between revisions of "TSQL Execution Plan"
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Match rows from two suitably sorted input tables and exploiting their sort order. | Match rows from two suitably sorted input tables and exploiting their sort order. | ||
| + | === table spool === | ||
| + | The Table Spool operator scans the input and places a copy of each row in a hidden spool table that is stored in the tempdb database and existing only for the lifetime of the query. If the operator is rewound (for example, by a Nested Loops operator) but no rebinding is needed, the spooled data is used instead of rescanning the input. | ||
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| + | Table Spool is a physical operator. | ||
=== Resources === | === Resources === | ||
* [http://msdn.microsoft.com/en-us/library/ms175913.aspx icons] | * [http://msdn.microsoft.com/en-us/library/ms175913.aspx icons] | ||
Revision as of 11:31, 6 April 2012
Contents
Hash Match
use each row from the top input to build a hash table, and each row from the bottom input to probe into the hash table, outputting all matching rows.
Clustered Index Scan
Scanning a clustered index, entirely or only a range.
Clustered Index Seek
Compute scalar
Compute new values from existing values in a row
Stream aggregate
Compute summary values for groups of rows in a suitably sorted stream.
Sort
Sort the input
Nested loops
For each row in the top (outer) input, scan the bottom (inner) input, and output matching rows.
Merge join
Match rows from two suitably sorted input tables and exploiting their sort order.
table spool
The Table Spool operator scans the input and places a copy of each row in a hidden spool table that is stored in the tempdb database and existing only for the lifetime of the query. If the operator is rewound (for example, by a Nested Loops operator) but no rebinding is needed, the spooled data is used instead of rescanning the input.
Table Spool is a physical operator.
