php - Optimising a big Wordpress site -

i'm looking @ optimising rather large site i've been adding , adding to. database has become pretty big (maybe 100,000 posts) , has started slowing down , giving me "mysql has gone away"errors. i've been reading database optimisation , have ready people saying should looking use 1-15 queries on page.

do people think suggestion handful of queries should used on page?

am correct in thinking every time use wordpress function such get_permalink() creating new query , new connection database?

i have loops in there literally loop through 100+ users @ time , use functions such get_user_meta() in these loops - mean literally making 100 database queries or somehow cached in wordpress?

with issues this, thing take caching out of hands of wordpress, , make server work.

software wordpress , drupal have own caching systems, , should enable them, them in use, there's still amount of overhead software load , serve page.

so suggest investigate server caching engine such varnish.

this dramatically reduce server load sites yours; if have lot of requests same page on , over, varnish take on caching , wordpess never have know page being requested. no more loading php , wordpress core every request, no more database session every request.

if back-end cms software starting go slowly, single effective way of speeding up.