Hi, With current master (8785ea0) I made some tests on a MySQL 5.5.37 server containing about 81000 databases and about 81000 users. In the mysql.db tables there are about 81000 grant entries; each one grants some wildcard access to databases starting with a certain pattern. I tested with root, since the reports we got about the server being slow seem to be occurring for root. Good news --------- First, the login. It takes about 7 seconds before seeing the initial page after login. In the navi panel, there is a db page selector with 107 page numbers. Going to any page takes about 7 seconds. Opening a db takes about 4 second (each db seems to contain about 31 tables). Browsing tables, grid editing, searching inside a table behave normally. Using Server > Databases works correctly, including switching pages. Problems -------- Going to a MyISAM table, Structure, and trying to change a column's structure takes 30 seconds before seeing the dialog for this column. Switching this table to InnoDB does not help. Database filter: I got mixed results. Sometimes it works (after about 10 seconds) but sometimes it stalls and does not find anything. I could not find a consistent way to reproduce. Server > Users: "Error in processing request. Error code: 500. Error text: Internal server error". -- Marc Delisle | phpMyAdmin