I don't see an index for expression.id.
-----Original Message----- From: brian [mailto:mysql-l...@logi.ca] Sent: Tuesday, July 03, 2012 12:28 PM To: mysql@lists.mysql.com Subject: Re: alternative to slow query On 12-07-02 09:33 PM, yoku ts wrote: > Hello, > > add index to expression1_id and expression2_id on expression_expression. > > it doesn't use index,following, > >> WHERE >> ee2.expression1_id = $ID >> OR >> ee1.expression2_id = $ID > Thank you for your reply. The table already has indexes on these columns, however: mysql db_lexi > show index from expression_expression\G *************************** 1. row *************************** Table: expression_expression Non_unique: 0 Key_name: PRIMARY Seq_in_index: 1 Column_name: id Collation: A Cardinality: 106191 Sub_part: NULL Packed: NULL Null: Index_type: BTREE Comment: *************************** 2. row *************************** Table: expression_expression Non_unique: 1 Key_name: expression2_id_idx Seq_in_index: 1 Column_name: expression2_id Collation: A Cardinality: 106191 Sub_part: NULL Packed: NULL Null: Index_type: BTREE Comment: *************************** 3. row *************************** Table: expression_expression Non_unique: 1 Key_name: type_lien_id_idx Seq_in_index: 1 Column_name: type_lien_id Collation: A Cardinality: 43 Sub_part: NULL Packed: NULL Null: YES Index_type: BTREE Comment: *************************** 4. row *************************** Table: expression_expression Non_unique: 1 Key_name: expression1_id_idx Seq_in_index: 1 Column_name: expression1_id Collation: A Cardinality: 106191 Sub_part: NULL Packed: NULL Null: Index_type: BTREE Comment: 4 rows in set (0.23 sec) -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql ________________________________ Notice: This communication may contain privileged and/or confidential information. If you are not the intended recipient, please notify the sender by email, and immediately delete the message and any attachments without copying or disclosing them. LBI may, for any reason, intercept, access, use, and disclose any information that is communicated by or through, or which is stored on, its networks, applications, services, and devices. -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
