Change created for one specific test case.
Fix various tests for DatabaseTestCase changes.
Make sure non-core tables are truncated by IntegrationTestCase::restoreDbTables().
Fixing more tests for DatabaseTestCase change.
Use table prefix when truncating tables in DatabaseTestCase.
Refactor DbHelper::truncateAllTables() to truncate non-core tables, and tweaks to DatabaseTestCase tests.
Add docs for optimization strategy.
Merge pull request #6331 from piwik/db_test_case_optimize

Optimize DatabaseTestCase by creating DB and tables only once (like IntegrationTestCase) so travis build will be faster.