#293 Support for @OutputServerName in sp_BlitzCache #419

hariscodes · 2016-08-10T15:00:53Z

Fixes #293 for sp_BlitzCache.

Changes proposed in this pull request:

Support for @OutputServerName
Updated error checking for @OutputDatabaseName variables for both linked and local servers

How to test this code:

Run procedure output with @expertmode = 1 (for comparison)
Run procedure with valid @OutputDatabaseName/SchemaName/TableName specified (should succeed in creating local table)
Run procedure with @OutputServerName specified as valid linked server along with other Output variables (should succeed in creating remote table on linked server)
Rerun both tests above without deleting testing tables to ensure that procedure doesn't try and create new table (it should dump results to the same table; tests IF EXISTS logic in permanent table creation)
Run procedure with invalid @OutputServerName (server that is not linked and random name; both should fail)
Run procedure with invalid local DB name (should fail)
Run procedure with invalid linked DB name (Specify valid @OutputServerName; should fail)

Use the output from the @expertmode = 1 run to compare the output on both the local and remote tables...they should be the same.

Has been tested on:

SQL Server 2008
SQL Server 2008 R2
SQL Server 2012
(UPDATE) SQL Server 2016

Catching up with DEV

Started working on this, brought out output logic into it's own block like I did with sp_Blitz. Not functional yet.

This variable now works on sp_BlitzCache! Same limitations as sp_Blitz when trying to populate an XML field cross server, so query plans return as NVARCHAR(MAX).

…reaks

hariscodes · 2016-08-12T18:44:47Z

Tested this on SQL Server 2016 (Got my instance connected to my domain) :)

BrentOzar · 2016-09-29T20:07:02Z

sp_BlitzCache.sql

+					BEGIN
+						IF EXISTS (SELECT server_id FROM sys.servers WHERE QUOTENAME([name]) = @OutputServerName)
+							BEGIN
+								SET @LinkedServerDBCheck = 'SELECT 1 WHERE EXISTS (SELECT * FROM '+@OutputServerName+'.master.sys.databases WHERE QUOTENAME([name]) = '''+@OutputDatabaseName+''')'


Does this work if someone only has permissions to a single database, but not to master.sys.databases? I think generally in linked server situations, the cross-server account users don't have a lot of permissions.

As long as they are in the Public role it should be fine. If the DBA/Vendor has removed all of the precreated roles for their own, the linked server account needs to have VIEW ANY DATABASE permission.

From the docs on sys.databases:

By default, the public role has the VIEW ANY DATABASE permission, allowing all logins to see database information. To block a login from the ability to detect a database, REVOKE the VIEW ANY DATABASE permission from public, or DENY the VIEW ANY DATABASE permission for individual logins.

BrentOzar

Looks great! Just a few small changes.

BrentOzar · 2016-09-29T20:09:40Z

sp_BlitzCache.sql

+          QueryText NVARCHAR(MAX),
+          QueryPlan XML,
+          NumberOfPlans INT,
+          NumberOfDistinctPlans INT,


Uh oh - looks like maybe this was started from an older version, and it didn't have all of the current fields. Can you add the ones from lines 2182-2187 in the last version, and test that?

Sure thing!

OK, just update the issue when that code has been added. (Just went in and checked and it still wasn't there, so noting in here in case you were missing that.)

BrentOzar · 2016-09-29T20:10:31Z

sp_BlitzCache.sql

+		BEGIN
+			SET @insert_sql = REPLACE(@insert_sql,''''+@OutputSchemaName+'''',''''''+@OutputSchemaName+'''''')
+			SET @insert_sql = REPLACE(@insert_sql,''''+@OutputTableName+'''',''''''+@OutputTableName+'''''')
+			SET @insert_sql = REPLACE(@insert_sql,'''DBCC FREEPROCCACHE ('' + CONVERT(VARCHAR(128), [PlanHandle], 1) + '');''','''''DBCC FREEPROCCACHE ('''' + QUOTENAME(CONVERT(VARCHAR(128), [PlanHandle], 1), CHAR(39)) + '''');''''')


Dumb question - what are we search/replacing this part for? (I'm guessing you found something neat during testing, but if there's an easier way to fix it than doing search/replace, I'm totally down with that - replacing in long strings can be pretty slow.)

Since I have to use sp_executesql on the other box:

EXEC('EXEC('''+@insert_sql+''') AT ' + @OutputServerName);

...I end up needing extra single-quotes in the dynamic SQL string to make it function.

For the Plan Handles and the Query Hashes, it's the same problem. Without the correct number of single-quotes I end up inserting Plan Handle/Query Hash with a pair of single quotes around it into the output table rather than the code itself.

EDIT: Was using brain upside down when I wrote this the first time...

I should also note that I did it this way for code reuse; and that performance was never an issue here since the insert_sql string is not insanely long or anything. If we were updating a ton of strings it would probably be an issue though.

Nah, you don't want to do that - let's not try to execute SQL on other servers. (I can see that being a security nightmare.)

BrentOzar · 2016-09-29T20:11:01Z

sp_BlitzCache.sql

-                                                    END + N' DESC '
-
-    SET @insert_sql += N' OPTION (RECOMPILE) ; '    
+			SELECT @insert_sql += N' ORDER BY ' + CASE @SortOrder WHEN 'cpu' THEN ' TotalCPU '


Should we still be doing an order by in the insert, come to think of it?

BrentOzar · 2017-01-16T11:47:34Z

This still hasn't been fixed after a few months, so I'm going to go ahead and close it. Thanks though.

Haris Khan added 4 commits August 8, 2016 10:42

Merge pull request #1 from BrentOzarULTD/dev

f48c38a

Catching up with DEV

BrentOzarULTD#293 sp_BlitzCache - Support for @OutputServerName

6fbcdd6

Started working on this, brought out output logic into it's own block like I did with sp_Blitz. Not functional yet.

BrentOzarULTD#293 sp_BlitzCache - Support for @OutputServerName

b4b449f

This variable now works on sp_BlitzCache! Same limitations as sp_Blitz when trying to populate an XML field cross server, so query plans return as NVARCHAR(MAX).

BrentOzarULTD#293 sp_BlitzCache - Dev Catch up to make sure nothing b…

9c4c091

…reaks

hariscodes mentioned this pull request Sep 22, 2016

sp_BlitzIndex - add OutputDatabaseName, SchemaName, TableName #221

Closed

BrentOzar reviewed Sep 29, 2016

View reviewed changes

BrentOzar requested changes Sep 29, 2016

View reviewed changes

BrentOzar closed this Jan 16, 2017

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

#293 Support for @OutputServerName in sp_BlitzCache #419

#293 Support for @OutputServerName in sp_BlitzCache #419

hariscodes commented Aug 10, 2016 •

edited

Loading

hariscodes commented Aug 12, 2016

BrentOzar Sep 29, 2016

hariscodes Sep 29, 2016

BrentOzar left a comment

BrentOzar Sep 29, 2016

hariscodes Sep 29, 2016

BrentOzar Oct 13, 2016

BrentOzar Sep 29, 2016

hariscodes Sep 29, 2016 •

edited

Loading

hariscodes Sep 29, 2016

BrentOzar Oct 13, 2016

BrentOzar Sep 29, 2016

BrentOzar commented Jan 16, 2017

#293 Support for @OutputServerName in sp_BlitzCache #419

#293 Support for @OutputServerName in sp_BlitzCache #419

Conversation

hariscodes commented Aug 10, 2016 • edited Loading

hariscodes commented Aug 12, 2016

Choose a reason for hiding this comment

Choose a reason for hiding this comment

BrentOzar left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

hariscodes Sep 29, 2016 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

BrentOzar commented Jan 16, 2017

hariscodes commented Aug 10, 2016 •

edited

Loading

hariscodes Sep 29, 2016 •

edited

Loading