MySQL vs PostgreSQL

MySQL runs on 4,172,167 ranked sites (41.8%); PostgreSQL on 10,506 (0.1%).

By rank tier
TierMySQLSharePostgreSQLShare
Top 1,000858.5%0<0.1%
Top 10,0001,18811.9%3<0.1%
Top 100,00014,74914.7%29<0.1%
Top 1,000,000229,32422.9%5080.1%
All ranked4,172,16741.8%10,5060.1%