sql_paging_limit() is deprecated in 1.7 all all its uses must be out completely from core in order to guarantee cross-db queries. Current uses are:

blocks/glossary_random/block_glossary_random.php: $LIMIT = sql_paging_limit($i-1, 1);
blocks/glossary_random/block_glossary_random.php: $LIMIT = sql_paging_limit($i-1, 1);
blocks/online_users/block_online_users.php: $groupselect ".sql_paging_limit(0,20);
blog/lib.php: $limit = sql_paging_limit($fetchstart, $fetchlimit);
course/report/participation/index.php: $sql .= ' '.sql_paging_limit($table->get_page_start(), $table->get_page_size());
enrol/authorize/locallib.php: $limit = ' ' . sql_paging_limit($table->get_page_start(), $table->get_page_size());
lib/datalib.php: $limit = sql_paging_limit($page, $recordsperpage);
lib/datalib.php: $limit = sql_paging_limit($limitfrom, $limitnum);
lib/datalib.php: $limit = sql_paging_limit($page, $recordsperpage);
mod/assignment/lib.php: $limit = sql_paging_limit($offset+1, 1);
mod/assignment/lib.php: $limit = ' '.sql_paging_limit($table->get_page_start(), $table->get_page_size());