showplan messages for query clauses

Use of certain Transact-SQL clauses, functions, and keywords is reflected in showplan output. These include group by, aggregates, distinct, order by, and select into clauses.

Use of certain Transact-SQL clauses, functions, and keywords is reflected in showplan output. These include group by, aggregates, distinct, order by, and select into clauses.

Table 5-1: showplan messages for various clauses

Message

Explanation

GROUP BY

The query contains a group by statement.

The type of query is SELECT (into WorktableN).

The step creates a worktable to hold intermediate results.

Evaluate Grouped type AGGREGATE

Evaluate Ungrouped type AGGREGATE.

The query contains an aggregate function.

“Grouped” indicates that there is a grouping column for the aggregate (vector aggregate).

“Ungrouped” indicates that there is no grouping column (scalar aggregate). The variable indicates the type of aggregate.

Evaluate Grouped ASSIGNMENT OPERATOR

Evaluate Ungrouped ASSIGNMENT OPERATOR

The query includes compute (ungrouped) or compute by (grouped).

WorktableN created for DISTINCT.

The query contains the distinct keyword in the select list and requires a sort to eliminate duplicates.

WorktableN created for ORDER BY.

The query contains an order by clause that requires ordering rows.

This step involves sorting.

The query includes on order by or distinct clause, and results must be sorted.

Using GETSORTED

The query created a worktable and sorted it. GETSORTED is a particular technique used to return the rows.

The sort for WorktableN is done in Serial.

The sort for WorktableN is done in Parallel.

Indicates how the sort for a worktable is performed.