public void setMatchKey(String matchKey) {
        this.matchKey = matchKey;
    }
<p>
A key that allows grouping of multiple input attributes into a unified matching group.
</p>
<p>
For example, consider a scenario where the source table contains various addresses, such as
<code>business_address</code> and <code>shipping_address</code>. By assigning a <code>matchKey</code> called
<code>address</code> to both attributes, Entity Resolution will match records across these fields to create a
consolidated matching group.
</p>
<p>
If no <code>matchKey</code> is specified for a column, it won't be utilized for matching purposes but will still
be included in the output table.
</p>

@param matchKey
       A key that allows grouping of multiple input attributes into a unified matching group. </p>
       <p>
       For example, consider a scenario where the source table contains various addresses, such as
       <code>business_address</code> and <code>shipping_address</code>. By assigning a <code>matchKey</code>
       called <code>address</code> to both attributes, Entity Resolution will match records across these fields
       to create a consolidated matching group.
       </p>
       <p>
       If no <code>matchKey</code> is specified for a column, it won't be utilized for matching purposes but will
       still be included in the output table.
aws-java-sdk-entityresolution/src/main/java/com/amazonaws/services/entityresolution/model/SchemaInputAttribute.java