title: Problems using ClickHouse
body: <p>We are revamping our existing system, which uses MYSQL DB to deal with the following type of data.</p>
  
  <ul>
  <li>transaction and order related data</li>
  <li>customers information</li>
  <li>products information</li>
  </ul>
  
  <p>We need to query on these data and pull in statistical data, and also filter, facet and segment list and KPIs.</p>
  
  <p>We tried ClickHouse, Druid, DGraph did a few tests on sample data to benchmark and to check which DB fits our needs.</p>
  
  <p>Few things I liked about Druid DB are,</p>
  
  <ul>
  <li>Druid Search Queries: Which lists down all the matches along with the dimensions(column names) and count/occurrence for the same.
  Link: <a href="http://druid.io/docs/latest/querying/searchquery.html" rel="nofollow noreferrer">http://druid.io/docs/latest/querying/searchquery.html</a></li>
  <li>utf8mb4 support</li>
  <li>Full text search</li>
  <li>Case insensitive search</li>
  </ul>
  
  <p>We found ClickHouse to be faster when compared to MYSQL and Druid databases. But have the following problems.</p>
  
  <ul>
  <li>Unable to do druid-like-search queries (which return dimension and occurrences). Any workaround to achieve this?</li>
  <li>Case insensitive search. How do we handle this? ClickHouse is case-sensitive, right?</li>
  <li>utf8mb4 support? How do we save/store special characters or few emoji's which are not supported on utf8?
  <br/>We had similar issues in MYSQL, and changing the collation to utf8mb4 solved it. What do we in ClickHouse to achieve this?</li>
  </ul>
  
  <p>Your suggestions can help us overcome these challenges and make a better decision.</p>
  
  <p>Thanks in advance.</p>