title: SQL UPDATE, WHERE conditions limitation (index stop work)
body: <p>Index stop working if i have some multiple OR pairs like ((ID = 5 AND TEST_DATE = '2019-01-17 05:56:19.0'))</p>
  
  <p>SQL Where clauses has limitations? SQL optimizer decide to use full scan?
  Database query settings restrictions?</p>
  
  <p>I can split sql to small peaces.</p>
  
  <pre><code>EXPLAIN
        UPDATE TEST_TABLE
        SET MY_FLAG=1
        WHERE (ID = 1 AND TEST_DATE = '2019-01-15 01:24:01.0') ||
              (ID = 2 AND TEST_DATE = '2019-01-15 02:14:02.0') ||
              (ID = 3 AND TEST_DATE = '2019-01-16 03:32:08.0') ||
              (ID = 4 AND TEST_DATE = '2019-01-16 04:45:19.0') ||
              (ID = 5 AND TEST_DATE = '2019-01-17 05:56:19.0')
  </code></pre>
  
  <p>Explain results1: OR pairs > 200</p>
  
  <pre><code>(1, 'SIMPLE', 'TEST_TABLE', 'range', 'PRIMARY,test_date_index', 'PRIMARY', '8', NULL, 316, 'Using where');
  </code></pre>
  
  <p>Explain results2: OR pairs > 300</p>
  
  <pre><code>(1, 'SIMPLE', 'TEST_TABLE', 'index', NULL, 'PRIMARY', '8', NULL, 51425278, 'Using where');
  </code></pre>
  
  <p>Table strucute:</p>
  
  <pre><code>CREATE TABLE `TEST_TABLE` (
      `ID` BIGINT(20) NOT NULL AUTO_INCREMENT,
      `ATTR_ADDRESS` VARCHAR(255) NULL DEFAULT NULL,
      `ATTR_CITY` VARCHAR(40) NULL DEFAULT NULL,
      `ATTR_COUNTRY` VARCHAR(40) NULL DEFAULT NULL,
      `TEST_DATE` DATETIME NOT NULL,
      `MY_FLAG` BIT(1) NOT NULL DEFAULT b'0',
      PRIMARY KEY (`ID`),
      INDEX `test_date_index` (`TEST_DATE`),
      INDEX `MY_FLAG` (`MY_FLAG`)
  )
  COLLATE='utf8_general_ci'
  ENGINE=InnoDB
  ;
  </code></pre>