Does SQL Server Management Studio 2017 Contain a New Explain Feature

Question

TL;DR

I happened upon a feature in SQL Server Management Studio v17.9 which I was not aware of. It looks a bit like the EXPLAIN found in Oracle, PostgreSQL and MySQL. Where is this feature documented?

How to Turn The Feature On

I was running the following query with the options Include Actual Execution Plan (Ctrl + M) and Include Live Query Statistics turned on:

    SELECT sdes.session_id
          ,sdes.[status]
          ,sdes.login_name
          ,sdes.[host_name]
          ,sder.blocking_session_id
          ,sdb.name
          ,sdes.cpu_time
          ,sdes.logical_reads --optionally: + sdes.reads + sdes.writes
          ,sdes.last_request_start_time
          ,sdes.program_name
          ,sdes.session_id
          ,sder.request_id
          ,dest.[text]
    FROM   sys.dm_exec_sessions             AS sdes
           LEFT JOIN sys.dm_exec_connections     AS sdec
                ON  sdes.session_id = sdec.session_id
           JOIN sys.databases               AS sdb
                ON  sdes.database_id = sdb.database_id
           LEFT JOIN sys.dm_exec_requests  AS sder
                ON  sdes.session_id = sder.session_id
           CROSS APPLY sys.dm_exec_sql_text(sdec.most_recent_sql_handle) AS dest
    WHERE 1=1
    AND sdb.name = ''

Outcome

This produced four results tabs:

• Results
• Messages
• Live Query Statistics
• Execution Plan

Special Results Tab

When I switched to the Results tab, I noticed a result set just below the actual results which looks like this:

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Observations

If I turn on either the Include Actual Execution Plan (Ctrl + M) option or the Include Live Query Statistics option, then the SQL Server Explain isn't displayed. The "SQL Server Explain" is only displayed if both options are turned on.

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Questions

1. Can this feature be turned on without having to activate both Include Actual Execution Plan (Ctrl + M) option and the Include Live Query Statistics?
2. Where is this neat little feature documented?

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Prerequisites

The following components and/or software packages are involved in the scenario:

Server

• Windows Server 2016
• SQL Server 2016 SP1

Client

• Windows 10 Version 1807 (Build 17134)
• SQL Server Management Studio v17.9
  • Microsoft SQL Server Management Studio 14.0.17285.0
  • Microsoft Analysis Services Client Tools 14.0.1016.283
  • Microsoft Data Access Components (MDAC) 10.0.17134.1
  • Microsoft MSXML 3.0 6.0
  • Microsoft Internet Explorer 9.11.17134.0
  • Microsoft .NET Framework 4.0.30319.42000
  • Operating System 6.3.17134

SQL Server Management Studio v17.9

• Include Actual Execution Plan (Ctrl + M) turned ON
• Include Live Query Statistics turned ON

Answer 1

No, not a feature - it's turning one of these on:

SET SHOWPLAN_TEXT ON;  
SET STATISTICS PROFILE ON;

The SHOWPLAN_TEXT option and STATISTICS PROFILE option are well-documented and have been around for over a decade, but I don't know when SSMS started turning it on for the combo of live query plans and actual plans. I would consider it a bug.

Here's the SSMS bug I filed for it.