In FAST the indexerinfo and indexeradmin commands were very useful in basic management of the search index. Similarly it would be great if some information can be provided on index management for SP2013 search.

1. Power shell Command to verify the number of items in the index.
2. Post a crawl completion, how to verify if the content has been indexed. 
3. How to validate the count of documents which are yet to be indexed.
4. How to specifically manage the indexing service in 2013. 
5. In case the index status shows degarded, which powershell commands can help in root cause analysis.
6. In FAST occasionally row sync had to be done between the primary and secondary index rows. In SP2013 scenario, in case the indexed content on one of the rows gets corrupted, what steps can be followed to restore the backup content on the corrupted row.

Regards,

Jaya

Hi Jaya,

1. If you want to know the count of the items in the index, you could use the PowerShell in the article below.

The article below is about Script to report total number of indexed documents.

https://gallery.technet.microsoft.com/office/Script-to-report-total-88056b1b   

You also could use the CrawlLog.GetCrawlStatisticsByContentSource method, it will get crawled content statistics for each content source in the search service application.

There is a similar case:

https://social.msdn.microsoft.com/Forums/sharepoint/en-US/fa40f479-0a15-4667-9d9b-e56ec31f65d7/sharepoint-2013-number-of-items-on-the-index?forum=sharepointdevelopment

2. You could check the crawl log, if the content is in the crawl log, it has been indexed.

3. You could check the warnings and errors in the crawl log. For more detailed information, you could refer to the article below.

The article below is about viewing search diagnostics in SharePoint Server 2013.

https://technet.microsoft.com/en-us/library/JJ219611.aspx

4. If you want to know how to manage the index service, you could refer to the articles below.

The article below is about managing the index component in SharePoint Server 2013.

https://technet.microsoft.com/en-us/library/JJ862355.aspx

The article below is about Chapter 9 - Administering the Indexing Service.

https://msdn.microsoft.com/en-us/library/Bb727099.aspx

5. If you want to check the error when index status shows degraded, you could go to check the ULS log. (The path of ULS log: C:\Program files\Common Files\Microsoft Shared\Web Server Extensions\15\LOGS). You could do some research according to the details about the error.

More references:

The article below is about SharePoint Index Partition Degradation.

http://sharepointforthenondeveloper.blogspot.com/2015/01/sharepoint-index-partition-degradation.html

The article below is about SharePoint 2013 Search component degrade errors.

https://sharepointdeal.wordpress.com/2013/04/19/sharepoint-2013-search-component-degrade-errors/

6. If the content is the library or list, you could restore the library or list. For more detailed information, you could refer to the article below.

The article below is about Import a list or document library in SharePoint 2013.

https://technet.microsoft.com/en-us/library/Ee428322.aspx

You also could rebuild the search index. For more detailed information, you could refer to the articles below.

The article below is about Fixing a Corrupt Search Index.

https://blogs.perficient.com/microsoft/2009/04/fixing-a-corrupt-search-index/

The article below is about FAST Search Repair or Rebuild your Corrupt Index from FIXML?

https://mark7smith.wordpress.com/tag/rebuild-index/

Best regards,

Sara Fan