Aggregate Transformation Editor (Advanced Tab)
Use the Advanced tab of the Aggregate Transformation Editor dialog box to set component properties, specify aggregations, and set properties of input and output columns.
Note
The options for key count, key scale, distinct key count, and distinct key scale apply at the component level when specified on the Advanced tab, at the output level when specified in the advanced display of the Aggregations tab, and at the column level when specified in the column list at the bottom of the Aggregations tab.
In the Aggregate transformation, Keys and Keys scale refer to the number of groups that are expected to result from a Group by operation. Count distinct keys and Count distinct scale refer to the number of distinct values that are expected to result from a Distinct count operation.
To learn more about the Aggregate transformation, see Aggregate Transformation.
Options
- Keys scale
Optionally specify the approximate number of keys that the aggregation expects. The transformation uses this information to optimize its initial cache size. By default, the value of this option is Unspecified. If both Keys scale and Number of keys are specified, Number of keys takes precedence.
<div class="caption">
</div>
<div class="tableSection">
<table>
<colgroup>
<col style="width: 50%" />
<col style="width: 50%" />
</colgroup>
<thead>
<tr class="header">
<th><p>Value</p></th>
<th><p>Description</p></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td><p>Unspecified</p></td>
<td><p>The <strong>Keys scale</strong> property is not used.</p></td>
</tr>
<tr class="even">
<td><p>Low</p></td>
<td><p>Aggregation can write approximately 500,000 keys.</p></td>
</tr>
<tr class="odd">
<td><p>Medium</p></td>
<td><p>Aggregation can write approximately 5,000,000 keys.</p></td>
</tr>
<tr class="even">
<td><p>High</p></td>
<td><p>Aggregation can write more than 25,000,000 keys.</p></td>
</tr>
</tbody>
</table>
</div>
Number of keys
Optionally specify the exact number of keys that the aggregation expects. The transformation uses this information to optimize its initial cache size. If both Keys scale and Number of keys are specified, Number of keys takes precedence.Count distinct scale
Optionally specify the approximate number of distinct values that the aggregation can write. By default, the value of this option is Unspecified. If both Count distinct scale and Count distinct keys are specified, Count distinct keys takes precedence.
<div class="caption">
</div>
<div class="tableSection">
<table>
<colgroup>
<col style="width: 50%" />
<col style="width: 50%" />
</colgroup>
<thead>
<tr class="header">
<th><p>Value</p></th>
<th><p>Description</p></th>
</tr>
</thead>
<tbody>
<tr class="odd">
<td><p>Unspecified</p></td>
<td><p>The CountDistinctScale property is not used.</p></td>
</tr>
<tr class="even">
<td><p>Low</p></td>
<td><p>Aggregation can write approximately 500,000 distinct values.</p></td>
</tr>
<tr class="odd">
<td><p>Medium</p></td>
<td><p>Aggregation can write approximately 5,000,000 distinct values.</p></td>
</tr>
<tr class="even">
<td><p>High</p></td>
<td><p>Aggregation can write more than 25,000,000 distinct values.</p></td>
</tr>
</tbody>
</table>
</div>
Count distinct keys
Optionally specify the exact number of distinct values that the aggregation can write. If both Count distinct scale and Count distinct keys are specified, Count distinct keys takes precedence.Auto extend factor
Use a value between 1 and 100 to specify the percentage by which memory can be extended during the aggregation. By default, the value of this option is 25%.