291438 - Upgrades from 2.8 to 2.18.1 will have an extra index on the milestones table

Status: RESOLVED WORKSFORME

(Bugzilla :: Bugzilla-General, defect)

Description

[Max Kanat-Alexander]

When we upgrade from 2.8 to 2.18.1, we temporarily drop the
milestones.product_id field and replace it with a field called "milestones.product."

However, this field (milestones.product_id) had a multi-column index on itself
and milestones.value.

So when we drop the field, we now have an index on *just* milestones.value.

When we re-create the milestones.product_id index later, it will be re-created,
but with a funny name, like product_id_2.

This is already fixed for 2.19.3+ in bug 285722. For 2.18, we just need to drop
the index at the same time as we're dropping the column.

Comment 1

[Max Kanat-Alexander]

Oh, actually, investigating this, I've discovered why we never ran into this
before! The bz_drop_table indexes was silently fixing this bug for us, and still
is, in 2.18. :-)

So it only showed up in bug 285722 when I stopped doing the (now
no-longer-necessary, because of bug 290277) bz_drop_table_indexes.