Query execution was interrupted

Can you tell us more bout the technical specs of the hosting company. (php version, ...)

Query was "SELECT 1 FROM information_schema.tables WHERE (table_schema = :db_condition_placeholder_4) AND (table_name = :db_condition_placeholder_5)"

Seems that we do not have access to the information_schema database. Should Drupal take consideration of this behavior and provide a workaround ?

If this can help...

MySQL 5 should always have an information_schema database as far as I know. If it doesn't then the DB is broken beyond Drupal's help. I'd expect a more conventional error as well if there were a table or DB missing.

Does that query work if run outside of Drupal? If run as a non-prepared-statement?

Well it's not going to take a literal prepared statement. :-) You need to insert in the appropriate values for the two placeholders, with quotes as appropriate.

Maybe I didn't see it, but did you mention if you use webhosting or run an own root server?

Anyway, for :db_condition_placeholder_4 you should use a database the user has access to and for :db_condition_placeholder_5 you should use a table inside this database.

The thing is, in shared hosting we only have access to our database, not information_schema (unless you are on provate hosting) so query on information_shema database will fail.

Crell: I tried the query (with replaced placeholders) and it failed (under phpmyadmin), because permission to view information_schema are not granted, and we cannot get it granted.

I'm pretty sure this is nothing more then a performance issue. OVH runs several thousand databases on its clusters, and the information schema scales much worse then we anticipated. Tentatively marking this as a duplicate of #748340: MySQL-optimized tableExists() implementation.

See also #686196: Meta issue: Install failures on various hosting environments for some additional discussions.