Currently there are limits on the calls behind the scenes for connecting SQL databases through ESS:
MySQL for Windows: 8,192
Oracle for Windows: 8,000
SQLServer for Windows: 524,288
Actual Technologies MySQL for Mac OS X: 8,192
Actual Technologies Oracle for Mac OS X: 8,000
Actual Technologies SQLServer for Mac OS X: 8,000
Except for SQLServer, these limits are ridiculously low.
Although I consider this a bug, TSGAL asked me to post this here. The limits for MySQL are way too low for practical usage - it really limits the number of fields that can be used in an instance.
Please consider raising these limits significantly! The best way to do it would be a number in FileMaker Server that we can increase if we want, and this way by default you can keep the numbers small by default (for prevention of crashes) and allow us to increase as much as we wish.