View Single Post
  #1  
Old 05-31-2015, 08:16 PM
JamesAB JamesAB is offline
 
Join Date: Dec 2003
Posts: 125
Благодарил(а): 0 раз(а)
Поблагодарили: 0 раз(а) в 0 сообщениях
Default Need help optimizing a mySQL query

Here's the query I'm trying to optimize:
Code:
SELECT *
FROM vb3_jabvideo AS video
LEFT JOIN vb3_attachment AS attachment ON (video.attachmentid = attachment.attachmentid)
LEFT JOIN vb3_user AS user ON (attachment.userid = user.userid)
LEFT JOIN vb3_post AS post ON (post.postid = attachment.postid)
LEFT JOIN vb3_thread AS thread ON (post.threadid = thread.threadid)
WHERE video.isdeleted = 0 AND attachment.visible = 1 AND post.visible = 1 AND thread.visible = 1 
ORDER BY RAND() 
LIMIT 30
It's currently taking about 2 seconds. There are more than 60,000 rows in the vb3_jabvideo table.

I believe the heart of the problem is ORDER BY RAND()

Any mySQL experts out there that could offer advice for optimizing this query or another solution for selecting 30 random rows from this table?

Thanks for your help,
James
Reply With Quote
 
X vBulletin 3.8.12 by vBS Debug Information
  • Page Generation 0.01229 seconds
  • Memory Usage 1,762KB
  • Queries Executed 11 (?)
More Information
Template Usage:
  • (1)SHOWTHREAD_SHOWPOST
  • (1)ad_footer_end
  • (1)ad_footer_start
  • (1)ad_header_end
  • (1)ad_header_logo
  • (1)ad_navbar_below
  • (1)bbcode_code
  • (1)footer
  • (1)gobutton
  • (1)header
  • (1)headinclude
  • (6)option
  • (1)post_thanks_box
  • (1)post_thanks_button
  • (1)post_thanks_javascript
  • (1)post_thanks_navbar_search
  • (1)post_thanks_postbit_info
  • (1)postbit
  • (1)postbit_onlinestatus
  • (1)postbit_wrapper
  • (1)spacer_close
  • (1)spacer_open 

Phrase Groups Available:
  • global
  • postbit
  • reputationlevel
  • showthread
Included Files:
  • ./showpost.php
  • ./global.php
  • ./includes/init.php
  • ./includes/class_core.php
  • ./includes/config.php
  • ./includes/functions.php
  • ./includes/class_hook.php
  • ./includes/modsystem_functions.php
  • ./includes/functions_bigthree.php
  • ./includes/class_postbit.php
  • ./includes/class_bbcode.php
  • ./includes/functions_reputation.php
  • ./includes/functions_post_thanks.php 

Hooks Called:
  • init_startup
  • init_startup_session_setup_start
  • init_startup_session_setup_complete
  • cache_permissions
  • fetch_postinfo_query
  • fetch_postinfo
  • fetch_threadinfo_query
  • fetch_threadinfo
  • fetch_foruminfo
  • style_fetch
  • cache_templates
  • global_start
  • parse_templates
  • global_setup_complete
  • showpost_start
  • bbcode_fetch_tags
  • bbcode_create
  • postbit_factory
  • showpost_post
  • postbit_display_start
  • post_thanks_function_post_thanks_off_start
  • post_thanks_function_post_thanks_off_end
  • post_thanks_function_fetch_thanks_start
  • post_thanks_function_fetch_thanks_end
  • post_thanks_function_thanked_already_start
  • post_thanks_function_thanked_already_end
  • fetch_musername
  • postbit_imicons
  • bbcode_parse_start
  • bbcode_parse_complete_precache
  • bbcode_parse_complete
  • postbit_display_complete
  • post_thanks_function_can_thank_this_post_start
  • showpost_complete