Added hash index docs and test

fixes #41

Author: Carl Sverre

README.md

@@ -21,6 +21,7 @@ This package is currently in a pre-release beta, please use with caution and ope
   - [Shard Keys](#shard-keys)
   - [Sort Keys](#sort-keys)
   - [Unique Keys](#unique-keys)
+  - [Hash Keys](#hash-keys)
   - [Series Timestamps](#series-timestamps)
   - [Computed Columns](#computed-columns)
   - [Increment Columns without Primary Key](#increment-columns-without-primary-key)
@@ -338,6 +339,20 @@ Schema::create('table', function (Blueprint $table) {
 });
 ```
 
+### Hash Keys
+
+You can add a `hash key` to your tables using the third argument to the `index`
+function. Note that by default, indexes on Universal Storage Tables
+(Columnstore) are always hash indexes, so a simple `.index(foo)` is usually
+sufficient. On Rowstore tables this syntax is needed to create a hash index.
+
+```php
+Schema::create('table', function (Blueprint $table) {
+    $table->string('name');
+    $table->index('name', 'name_idx', 'hash');
+});
+```
+
 ### Series Timestamps
 To denote a column as a series timestamp, use the `seriesTimestamp` column modifier.
 

tests/Hybrid/CreateTable/MiscCreateTest.php

@@ -24,12 +24,14 @@ public function all_keys_are_added_in_create_columnstore()
         $blueprint = $this->createTable(function (Blueprint $table) {
             $table->string('primary')->primary('name1');
             $table->string('index')->index('name2');
+            $table->string('foo');
+            $table->index('foo', 'name3', 'hash');
             $table->string('fulltext')->fulltext('name5')->charset('utf8');
         });
 
         $this->assertCreateStatement(
             $blueprint,
-            'create table `test` (`primary` varchar(255) not null, `index` varchar(255) not null, `fulltext` varchar(255) character set utf8 not null, primary key `name1`(`primary`), index `name2`(`index`), fulltext `name5`(`fulltext`))'
+            'create table `test` (`primary` varchar(255) not null, `index` varchar(255) not null, `foo` varchar(255) not null, `fulltext` varchar(255) character set utf8 not null, index `name3` using hash(`foo`), primary key `name1`(`primary`), index `name2`(`index`), fulltext `name5`(`fulltext`))'
         );
     }