problem

For filling the materialized view of a table the temporary table siblings for that fill request is created.

Temporary tables are isolated into the calling request, and the table is deleted after the request, so basically there is no problem with that approach.

But in some cases (cron job request for example, all batch operations on tasks) multiple segment views for multiple tasks have to be created. Then the the error "exception 'PDOException' with message 'SQLSTATE[42S01]: Base table or view already exists: 1050 Table 'siblings' already exists'" happens.

solution

Drop siblings table before creation.