I think i found the reason why delete and hide question cost much time. The reason may be bellow
1. In function "qa_question_delete" of file app/post-update.php,it will recount all the quesions and answers ,not directly increase(decrease) num +1/-1,this will cause whole table scan when recount, Do not know why use this way to do this.
2.By the way, I found in function qa_update_counts_for_q ,it will call five child fuction to update same table , is there possible merge these child into one sql opration ?
function qa_question_delete($oldquestion, $userid, $handle, $cookieid, $oldclosepost = null)
{
require_once QA_INCLUDE_DIR . 'db/votes.php';
if ($oldquestion['type'] != 'Q_HIDDEN')
qa_fatal_error('Tried to delete a non-hidden question');
$params = array(
'postid' => $oldquestion['postid'],
'oldquestion' => $oldquestion,
);
qa_report_event('q_delete_before', $userid, $handle, $cookieid, $params);
if (isset($oldclosepost) && ($oldclosepost['parentid'] == $oldquestion['postid'])) {
qa_db_post_set_closed($oldquestion['postid'], null); // for foreign key constraint
qa_post_unindex($oldclosepost['postid']);
qa_db_post_delete($oldclosepost['postid']);
}
$useridvotes = qa_db_uservote_post_get($oldquestion['postid']);
$oldpath = qa_db_post_get_category_path($oldquestion['postid']);
qa_post_unindex($oldquestion['postid']);
qa_db_post_delete($oldquestion['postid']); // also deletes any related voteds due to foreign key cascading
qa_update_counts_for_q(null);
function "qa_update_counts_for_q" will recount all various count use sql
/**
* Perform various common cached count updating operations to reflect changes in the question whose id is $postid
* @param $postid
*/
function qa_update_counts_for_q($postid)
{
if (isset($postid)) // post might no longer exist
qa_db_category_path_qcount_update(qa_db_post_get_category_path($postid));
qa_db_qcount_update();
qa_db_unaqcount_update();
qa_db_unselqcount_update();
qa_db_unupaqcount_update();
qa_db_tagcount_update();
}
