guys, i have some queries like this: SELECT doc_hash_key FROM mov_documentos WHERE doc_hash_key LIKE "j;1;$;294007/3nfe-1%" UNION SELECT doc_hash_key FROM mov_documentos WHERE doc_hash_key LIKE "j;1;%;294007/3nfe-1%" UNION SELECT doc_hash_key FROM mov_documentos WHERE doc_hash_key LIKE "j;1;%;%294007/3nfe-1%" UNION SELECT doc_hash_key FROM mov_documentos WHERE doc_hash_key LIKE "%;%;$;%294007/3nfe-1%" UNION SELECT doc_hash_key FROM mov_documentos WHERE doc_hash_key LIKE "%;%;%;294007/3nfe-1%" UNION SELECT doc_hash_key FROM mov_documentos WHERE doc_hash_key LIKE "%;%;%;%294007/3nfe-1%" LIMIT 1 it's a search about a document number, but the problem is.... the first query at first line (with % at end of the query) return really fast, but executing others queries are very slow, the question is could we optimize this kind of query, since limit=1 row? the explain of this query: idselect_typetabletypepossible_keyskeykey_lenrefrowsExtra1PRIMARY mov_documentosrangePRIMARYPRIMARY771Using where; Using index2UNION mov_documentosrangePRIMARYPRIMARY77625612Using where; Using index3UNION mov_documentosrangePRIMARYPRIMARY77625612Using where; Using index4UNION mov_documentosindexPRIMARY771798490Using where; Using index5UNION mov_documentosindexPRIMARY771798490Using where; Using index6UNION mov_documentosindexPRIMARY771798490Using where; Using indexUNION RESULT <union1,2,3,4,5,6>ALL -- Roberto Spadim