Affects Version/s: None
Fix Version/s: 1.9.0
Queries against INFORMATION_SCHEMA.TABLES and INFORMATION_SCHEMA.VIEWS slow down as the number of views increases.
BI tools like Tableau issue a query like the following at connection time:
The time to query the information schema tables degrades as the number of views increases. On a test system:
This can result in a single connection taking more than a minute to establish.
The problem occurs because we read the view file for every view and this appears to take most of the time.
Querying information_schema.tables does not, in fact, need to open the view file at all, it merely needs to get a listing of the view files. Eliminating the view file read will speed up the query tremendously.