Crawled Vs Managed properties: Search

1. How to create crawled and managed properties?
2. Are managed properties works at web application, site collection and site level?
3. How to map crawled properties with managed properties?
4. When full crawl is required?
5. Automatically creation of managed properties not supports what are all data types?
6. New features introduced in SP2013?
7. Is full crawl required for each map between crawled and managed property?
8. Difference between creating crawled property at SSA level and site collection level?
9. I have created one managed property of type “Text”. As per the current requirement I want to change it “Choice”. Is it possible?
10. I have created one site column of type “Single line of text”. As per the new feature introduced from the sharepoint 2013, automatically managed property will create for each site column creation. So far everything is clear. Now my question is will change the data type of managed property as changed at the site column level?
11. I have two different lists in site and there is one common field in both the list. Now, I want to map that field to the managed property?
12. Limitations on automatically creation of managed property for the site columns?

New features introduced on managed and crawled properties in SP2013?

From SP2013 onwards, only site columns that contain values will automatically become managed properties when they are crawled and full crawl is required.

In sp2010, whenever a new item was discovered during a crawl, users would have to manually create a new managed property, and map this to the corresponding crawled property.

What is the use of creating managed properties and why mapping required to the crawled properties?

Crawled properties are useless(means can’t be searchable/not us in Refinable)  without mapping it to the Managed properties and next point why mapping required is we can assign behaving similar ways of crawled properties to one managed properties.

To include the content and metadata of crawled properties in the search index, you map crawled properties to managed properties.

Example: Modified By, Created By and Author crawled properties behaves in similar way. Rather performing individual assign all 3 to one managed property called “Author” [see the below image]

Is full crawl required for each map between crawled and managed property?
Yes, Full crawl should be required.

When full crawl is required?
When you create a new managed property, or when you change certain settings on existing managed properties, a full crawl must complete before the managed property and its value is included in the search index.

When you have changed a managed property, or when you have changed the mapping of crawled and managed properties, the site must be re-crawled before your changes will be reflected in the search index. Because your changes are made in the search schema, and not to the actual site, the crawler will not automatically re-index the site.

Are managed properties works at web application, site collection and site level?
At site collection level.

Automatically creation of managed properties not supports what are all data types?
Managed properties are created automatically for site columns that contain values during crawl and it’s mapped to crawled properties (Note: All spaces are removed). But automatic creations of managed properties are not supported for the following site column types:

• Lookup
• Calculated
• Task outcome
• Summary Links data
• Rich media data for publishing

Difference between creating managed properties at site collection level and SSA level?

Big differences between managed properties created in the site collection versus the SSA are that when you create new managed properties in the site collection they have the below limitations you should be aware of:

• They can only be text and Yes/No
• They cannot be sortable
• They cannot be refinable
• They cannot allow multiple values
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I have created one site column of type “Single line of text”. As per the new feature introduced from the sharepoint 2013, automatically managed property will create for each site column creation. So far everything is clear. Now my question is will change the data type of managed property as changed at the site column level?
I have created a site column name:

Column name: MyDateTimeCol

Managed property Name: MyDateTimeColOWSDATE

And changed the date time column type to “Choice”

Column name: MyDateTimeCol

Managed property name: MyDateTimeColOWSCHCS

Note: What I observed is managed property will create for each field type change.

Auto-generated managed property is by default non-refinable.

Limitations on automatically creation of managed property for the site columns?
Limitation#1:

Managed properties are automatically created for the site columns but drawback here is they generated is always of “text” data type only.

Means by which data type if we create the site column, the managed property should create with of same type. But by default sharepoint generate the “text” data type.

Example: I have created a site column of data type “Choice”. Managed property generated for this choice column is of “Text” type.

We cannot change the types of managed properties once generated.

Example: I have created a site column of data type “Choice”. Managed property generated for this choice column is of “Text” type and then tries to change the type. Not possible.

I have created a managed property of type “Text” at SSA level and try to change the type. Not possible.

Limitation#2:

We cannot set the refinable.

I have created one managed property of type “Text”. As per the current requirement I want to change it “Choice”. Is it possible to make changes for the existing one?
Am sure it is not possible with CA. Will confirm on through PowerShell script.

How to change the type of managed property once generated/created?

Through browser it is not possible to change the type of the managed properties. Only way is through PowerShell script.

What are all the ways to create crawled properties?

Crawled properties are added automatically by the crawl components

Cannot be added via CA or search admin pages

Can be added via PowerShell script