Optimise image import

Need to optimise the speed of the image import. It seems like if the image file names do not use standard pattern the query attempt to lookup the image attribute value by VAL which leads to slow queries. We need to optimise this query so that additional criteria on the index field CODE is used as well.

Quick comparison on 0.5m attributes in query times:

mysql> select productent1_.CODE as col_0_0_ from TPRODUCTATTRVALUE attrvaluee0_, TPRODUCT productent1_ where attrvaluee0_.PRODUCT_ID=productent1_.PRODUCT_ID and attrvaluee0_.VAL='341260.jpg';
Empty set (5,65 sec)

mysql> select productent1_.CODE as col_0_0_ from TPRODUCTATTRVALUE attrvaluee0_, TPRODUCT productent1_ where attrvaluee0_.PRODUCT_ID=productent1_.PRODUCT_ID and attrvaluee0_.CODE like 'IMAGE%' and attrvaluee0_.VAL='341260.jpg';
Empty set (0,19 sec)