SharePoint Search – a look behind the scene Part IV

Part IV: Last part with a summary and some further issues

In the last parts of the series “SharePoint Search – a look behind the scene” (Part I , Part II , Part III) we have seen how SharePoint interacts with the SQL Server and which data is stored in which SQL Server Database belonging to the Search Service.

In Part III I show where custom managed properties belonging to an object are stored and how SharePoint handles this correlation. As one of the missing parts now let´s have a look at social Tags. The social Tags are stored in the UserProfile and not within the content. So for me it was interesting to see, that in the Search database the social Tags information is stored together with the content information in one table. The Table is the MssDocResults table in the Search_Service_Application_PropertyStoreDB. Folowing link shows a description of the table. http://msdn.microsoft.com/en-us/library/dd773971(v=office.12).aspx  The column PopularSocialTags contains the Tags given from the users.

Following example shows a T-SQL Search for the tag “I like it”:

SELECT * FROM [Search_Service_Application_PropertyStoreDB].[dbo].[MSSDocResults]

WHERE[PopularSocialTags] like '%I like it%'

So what we also see here is that this table is just “de-normalized”. For example the tag “SQL Server” and not only its ID / key is stored in the table MSSDocResults.

This is because of performance issues. Search is read optimized and it’s faster to deliver the data / relation from content and social Tags without doing joins before.

The keyword “Performance” brings me to the next point. During this “look behind” series we see, and that’s also the information SQL reports give us, that some tables are more frequently used and have a bigger impact in the context of search performance.

There is a really good article on which index is frequently used on MSDN. Most frequently used tables by search queries are:

-          dbo.MSSDocProp

-          dbo.MSSDocResults

-          dbo.MSSOrdinal

in the Search_Service_Application_PropertyStoreDB.

So if performance is a bottleneg it can be helpful placing this tables / index on a separate filegroup on a fast disksubsystem.

Another interesting part is the security. In case of a high sensitive environment we have to see clear which data is placed in which database and how it is protected. Communication between SharePoint Application Server and the SQL Server SharePoint Search databases is not really critical. The search requests are compiles in the BLOB Data as shown in Part I. But a maybe critical point is, that the data coming from external systems via BCS are placed clear text in the Search_Service_Application_PropertyStoreDB / table: dbo.MSSDocProps

this can be an issue. Details see Part III.

See the complete post inc. the hands-on lab as webcaste here:

SQL Server 2012 Filestream, Filetable and the added value with SharePoint 2010

I wrote about the new SQL Server 2012 Filetable feature based on Filestream, which was already been coming with the last version SQL Server 2008, before (see here: LINK ). Now let’s see Filetable together with SharePoint in action.

First we have to activate Filetable which is not been active per default after installing SQL Server 2012. How to activate this can be found here: LINK .

My settings are:

-          There is a database named “FileStreamDemo”.

-          In the “options” menu you can see that there is a Filestream directory named  “FileStreamData”

-          There is a table called “dbo.FileTableData” which points to the FileStreamData directory:

CREATE TABLE [dbo].[FileTableData] AS FILETABLE ON [PRIMARY] FILESTREAM_ON [FileStreamDemoGroup1]

WITH

(

FILETABLE_DIRECTORY = N'FileTableData', FILETABLE_COLLATE_FILENAME = SQL_Latin1_General_CP1_CI_AS

)

-          NON_TRANSACTED_ACCESS = FULL, that allowed us interact with the data in the filetable directory bypassing the SQL Server API and use the windows explorer direct.

-          The script in the background shows the create script for the database. We can see that the database files *.mdf and *.ldf are placed in a different directory than the Filestream data.

I placed several DEMO files in the Filestram directory:

If we now query the table “dbo.FileTableData” the result is:

The columns are fixed and base on the propertys coming from the NTFS file system:

Column Name	Data Type
stream_id	uniqueidentifier ROWGUIDCOL
file_stream	varbinary(max) FILESTREAM
name	nvarchar(255)
path_locator	hierarchyid
creation_time	datetimeoffset(7)
last_write_time	datetimeoffset(7)
last_access_time	datetimeoffset(7)
is_directory	bit
is_offline	bit
is_hidden	bit
is_readonly	bit
is_archive	bit
is_system	bit
is_temporary	bit

Each FileTable includes also these computed (read-only) columns:

Column Name	Data Type
parent_path_locator	hierarchyid
file_type	nvarchar(255)
cached_file_size	bigint

So we see that the content from FileStream directory is returned as BLOB data placed in the column “file_stream” as varbinary(max). By the way: the data placed in here is automatic part of the backup and restored process.

If we now use BCS to connect SharePoint to this database table we have two issues:

1.       We are not able to bring the content directly to the user without writing code that extracts / transforms the BLOB data.

2.       Using SharePoint to unwrap the BLOB data generates load on our SharePoint. The data must be load from SQL Server / Filesystem to SharePoint and from the SharePoint Server to the Client.

These two issues will have the same answer:

Let’s point to the data in the file-system using the given information. That means only the metinformation where the file is placed is transferred and the client picks up the data directly from where it is stored.

-          In scenario 1 the BLOB data is transferred via SharePoint.

-          Scenario 2 shows the way only the metinformation (blue arrows) is transferred via SharePoint and the user access the content directly.

Scenario 2 is what I will show now. The metinformation where the data is located is not part of the data in the “dbo.FileTableData” table. Also there are some columns we do not need to transfer via BCS to our SharePoint. So let’s write a SQL query which is given as the needed and filtered information:

1.  SELECT

2.  stream_id,

3.  name,

4.  file_type,

5.  cached_file_size,

6.  creation_time,

7.  last_write_time,

8.  last_access_time,

9.  is_directory,

10. 'file:\\DEMO2010A\FileStream\FileStreamData\FileTableData\' + name AS Link

11. FROM dbo.FileTableData

The line 10 brings the “magic” within this. This T-SQL call generates for every entry in the “dbo.FileTableData” table a link to the original data in the Filesystem. This link is attached as a new column called “Link”:

This query is now used to create a view called “FileTableView”.

Next step is now connection this view via BCS to SharePoint. I do this using SharePoint Designer to create a new External Content Type. How to create External Content Types and handling BCS is not part of this post. If you need help within this just contact me or have a look here: LINK .

So here is my solution:

As you can see I created an External Content Source called “FileTableData” which is based on the view “FileTableView”. For this use case I only need a ReadList and a ReadItem operation.

Publishing this External Content Type to a SharePoint External List (and of course doing some XSL customizing) generates a list looking like this which shows exactly the content of the FileStream directory:

Clicking the “Link” given to each entry opens the document / folder. The access happens as shown in PIC 4 directly to where the content is stored.

Resume:

This is an interesting way bringing data into a SharePoint environment without blowing up the content databases of SharePoint. This data can also be protected with SQL Server backup and recovery tools. But of course there a several 3th Party Tools doing this ore similar thing with more features around. Anyway, for me it’s a create feature and an additional option in data management.

See this post as webcaste here:

SharePoint Search – a look behind the scene Part III

Part III: SharePoint Search and BCS

(...which data is stored in context of crawled and managed properties in the SharePoint Search databases?)

In the second post of this series we see that the metadata shown in the result-set is stored in the SQL Server, even the data is coming from an extern BCS source. The given metadata like “name”, “description” etc. is stored in the PropertyBlob field explained in the first post. But this Blob only contains data which are part of the managed property “HitHighlightedSummary”. What happened now if we add a crawled property coming from a BCS source to a managed property?

Situation:

We have an External Content Source called “LOB2”. This content source is connected to an SQL Server database called “MiCLAS_TEST”.

The External Content Source contains the table called “cis.Vorgang_z”

If we now search for example the term “330114” witch is a value from the column “VorNummer” we get that result in SharePoint Search:

Catching the call with SQL Server Profiler (as described in Part II) and query it in SQL Server Management Studio it looks like this:

The PropertyBlob in this case contains the following data as varbinary:

0x020200EEFFFE7F99010000BD0010000080024078DAC590314BC36018841F639A96125408A50E0E19BA65B198A14310A4140A828242A0434B054104ADAE6EDF3F4F9FA420F41734C7BD977BBF5BDE6B9AA689801B4918CADE819C1387849833DAD97ED75D2671240106EEFB5CC8DAFFB44B24A2161BAE744FE24EDC3215A55B8EFC921FBE78E7931D1FE4CCF5DFFCF2A6FFD39F1A35CFBCF0C803AF62C1B6BB7FED88BD7AE08D11993D8D75B93A0999BC3CA89922A414E64ADF66763AB3DF7F7557D96565BFF766E78C58A97BBEC92717006452D3CBBACA8100805882AFCDCB81

If we know add crawled propertys to a managed propertys the PropertyBlob chaned¹. So were are this informations stored used to generate the updated Property Blob? (The update happens while fullcrawling the content source) The answer is the table “dbo.MSSDocProps“ in the „Search_Service_Application_PropertyStoreDB“.

Lets have a look using the DocId 2056 from the call above:

(for a better undestrand I alsoadd the “FriendlyName” column from the table dbo.MSSManagedProperties to the query )

USE Search_Service_Application_PropertyStoreDB_b506dce49c514f8899ae51e503889885

SELECT v2.FriendlyName,

         v1.*

FROM dbo.MSSDocProps v1, Search_Service_Application_DB_dd13ba19a7bb4ffaafcc3e626e73c949.dbo.MSSManagedProperties v2

WHERE DocId = 2056

and v1.PID = v2.PID

Now I map some crawled property to managed properties:

After a full crawled I execute the query again:

In case of the “LOB2Date” and the “LOB2Cur” values you can see that the data is in the IIVal column. The “LOB2Bez” value is clear text in the strVal2 column. LOB2Date is a cryptic datetime value based on the datatype DateTime Structure. LOB2Cur is a decimal value.

¹The updated PropertyBlob now contains the following:

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

So we see all the content contained in managed metadata is stored in the „Search_Service_Application_PropertyStoreDB“ database, even the data is coming from an extern BCS source. This is intresting for some security issues  (there will be a separate post about this soon)and also for SQL Server maintainence and index defragmentaion. There is a very good article about this availibel on blogs.msdn: LINK

See the complete post inc. the hands-on lab as webcaste here: