I think it should be also possible to use Doctrine's schema manager for that, just as we do it e.g. in our migrations:

Nice mention!

With Doctrine as feature, but not so much experience, i tried some things and this is what i found out.

Create a schmema from inside the code is a heavy lifting for the database in term of number of requests. Following works, but it would be necessary to cache that schema over the whole classes rebuild process.

$schema = $this->db->getSchemaManager()->createSchema();
$table = $schema->getTable($table);
$indexExists = $table->hasIndex($indexName);

Another solution is to use the SchemaManager directly like this. In this approach, the $tableName must be lowercase.

$indexes = $this->db->getSchemaManager()->listTableIndexes($table);
$indexExists = \in_array(strtolower($tableName), \array_keys($indexes))

This results in something like the following, which seems okay for me. It would replace the ADD INDEX/DROP INDEX requests by this SELECT requests (when nothing changes).

SELECT NON_UNIQUE AS Non_Unique, INDEX_NAME AS Key_name, COLUMN_NAME AS Column_Name, SUB_PART AS Sub_Part, INDEX_TYPE AS Index_Type FROM information_schema.STATISTICS WHERE TABLE_NAME = '...' AND TABLE_SCHEMA = 'pimcore' ORDER BY SEQ_IN_INDEX ASC

Both work. The second approach is less invasive to the code. Any suggestions?

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