Couple of weeks back I released Powershell cmdlets for DocumentDB in Github (Further info on this can be found in my blog here). Today I merged & added Automatic Indexing & IndexingMode parameters to the Add-DocumentCollection Cmdlet to the project in the module.
https://github.com/savjani/Azure-DocumentDB-Powershell-Cmdlets
Azure DocumentDB collections are auto-indexed by default allowing the developers to focus on the application development & not worry about the schema or index definition for the database. Automatic indexing of documents is enabled by consistent, write optimized, lock free, and log structured index maintenance techniques.
Anyone who has worked on databases would know, while indexes are useful to expedite querying, it is an additional overhead to write, maintain & store indexes. Hence it is important & efficient that we use indexing wisely & do not index attributes, which may never be used for querying or filtering.
Secondly DocumentDB supports two modes for Indexing viz Consistent (synchronous mode) v/s Lazy (asynchronous mode). If you are someone like me who has a database background, you would know that for continuous transactional OLTP workload we prefer to have Consistent indexing wherein the indexes are updated & maintained as data is inserted, updated or deleted. However for batch Datawarehousing type workloads we prefer to drop the index, load the data & recreate the index which will ensure to give us the best write performance. Similarly in DocumentDB if we intend to perform bulk load of the documents the write performance would be improved with Indexing Mode set to Lazy as compared to synchronous consistent mode.
At the time of writing this blog, AutoIndexing & IndexingMode settings are only supported during creation of collections & cannot be altered after collection is created. hence it is important that we plan & choose the right setting for our collection while creating it.
To support these settings during creating of collection using Powershell, I have added the following Optional parameters in Add-DocumentCollection Cmdlet.
AutoIndexing – ($true or $False) : This parameter is used to specify whether we want Automatic Indexing to be turned ON or OFF in the collection. It is optional parameter & if omitted, Automatic Indexing is turned ON by default.
IndexingMode – (Consistent or Lazy): This parameter is used to specify the IndexingMode for the collection. It is optional parameter & if omitted it is set to Consistent by default.
A good reference for DocumentDB Indexing Policy is following article from Product Group
https://azure.microsoft.com/en-us/documentation/articles/documentdb-indexing-policies/
Usage:
Creating a New Database & New Document Collection with default AutoIndexing & IndexingMode
Import-Module ‘C:\Users\pariks\Documents\GitHub\Azure-DocumentDB-Powershell-Cmdlets\Azrdocdb\Azrdocdb1\bin\Debug\Azrdocdb.dll’
$ctx = New-Context -Uri <uri> -Key <key>
$db = Add-Database -Context $ctx -Name “DocDBPS2”
$coll = Add-DocumentCollection -Context $ctx -DatabaseLink $db.SelfLink -Name “DocCollPS”
Get-database -Context $ctx -SelfLink $db.SelfLink | ft
Creating a New Database & New Document Collection & Setting Automatic Indexing Policy
Import-Module ‘C:\Users\pariks\Documents\GitHub\Azure-DocumentDB-Powershell-Cmdlets\Azrdocdb\Azrdocdb1\bin\Debug\Azrdocdb.dll’
$ctx = New-Context -Uri <uri> -Key <key>
$db = Add-Database -Context $ctx -Name ‘DocDB’
$coll = Add-DocumentCollection -Context $ctx -DatabaseLink $db.SelfLink -Name ‘DocCollPS’ -AutoIndexing $true
Get-database -Context $ctx -SelfLink $db.SelfLink | ft
Creating a New Database & New Document Collection & Setting Automatic Indexing Policy & IndexingMode
Import-Module ‘C:\Users\pariks\Documents\GitHub\Azure-DocumentDB-Powershell-Cmdlets\Azrdocdb\Azrdocdb1\bin\Debug\Azrdocdb.dll’
$ctx = New-Context -Uri <uri> -Key <key>
$db = Add-Database -Context $ctx -Name ‘DocDB’
$coll = Add-DocumentCollection -Context $ctx -DatabaseLink $db.SelfLink -Name ‘DocCollPS’ -AutoIndexing $true -IndexingMode ‘Lazy’
Get-database -Context $ctx -SelfLink $db.SelfLink | ft
Hope this Helps 
Parikshit Savjani
Premier Field Engineer