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PREVIOUS

Preview Feature

Comment Script is a preview feature and is only available in the DAX Studio preview build. Its syntax and behavior may change before the final release.

PREVIOUS is an assertion operand that refers to the preceding batch that executed a query. DAX Studio automatically captures that batch's result set and Server Timings, so no BASELINE command or name is needed.

Syntax​

--> ASSERT TABLE [UNORDERED|PARTIAL] PREVIOUS
--> ASSERT ROWCOUNT   [=|<|>|<=|>=] PREVIOUS [* <factor>]
--> ASSERT DURATION   [=|<|>|<=|>=] PREVIOUS [* <factor>]
--> ASSERT SE_CPU     [=|<|>|<=|>=] PREVIOUS [* <factor>]
--> ASSERT SE_QUERIES [=|<|>|<=|>=] PREVIOUS [* <factor>]
--> CLEARCACHE
EVALUATE /* version 1 */
--> GO
--> CLEARCACHE
--> ASSERT TABLE PREVIOUS
--> ASSERT DURATION <= PREVIOUS * 1.1
EVALUATE /* version 2 */

Command-only batches and SHOW DEPENDENCIES or SHOW DIAGRAM batches are skipped because they do not execute a query. A reference with no earlier query is an error.

Use PREVIOUS for progressive tuning where each version is compared with the one immediately above it. Use a named BASELINE when several candidates must all be compared with one fixed original.