+1, once you get the right indices in place, MySQL 4.x would scale just fine to millions of rows per table. Innodb and Percona were even better. Maatkit was ama

+1, once you get the right indices in place, MySQL 4.x would scale just fine to millions of rows per table. Innodb and Percona were even better. Maatkit was amazing for tuning, as was xdebug. When you just had expensive queries that were already optimized, you’d use IPVS, haproxy, apache, or RR DNS to help. This was before nginx existed. Static caching pages using Perl scripts to crawl the site and write out everything static as html files worked well too. Varnish was a real game-changer when that came out. Edit: forgot about Gearman for distributing work as well. Now people probably build the same types of things using SQS and functions. PHP was never the bottleneck, and the web could definitely “feel” faster back then on hardware an order of magnitude or two slower than we have today with these >10MiB index pages, CDNs and parallel downloads be damned.