tree b1438e26b9fe23f6d85930808422268e736c7835
parent 0806f7366e068ddb4342e24a9545533a48c212e7
author Bryan Pendleton <bpendleton@apache.org> 1466265620 +0000
committer Bryan Pendleton <bpendleton@apache.org> 1466265620 +0000

DERBY-6890: ALTER TABLE DROP COLUMN corrupts secondary index collation data.

During ALTER TABLE DROP COLUMN, we rebuild all the indexes on the table. Some
indexes may be entirely dropped, some indexes may be rebuilt with a subset
of columns, some indexes are simply rebuild with essentially the same content.

The issue is that the index rebuild logic was incorrectly setting the
collation data for each index. So the indexes had the right data, but the
wrong collation information, causing them to be damaged.

This change moves the computation of the index collation ids out of the
setUpAllSorts method, into the getAffectedIndexes method, where it is simpler
to compute the index collation ids appropriately, because the code in that
location already has logic to manipulate both the old (pre-DROP) and new
(post-DROP) table descriptions, and so it is straightforward to compute the
correct collation ids there.

As part of this change, an old test case in CollationTest2, which was marked
with the comment "this test does not work yet", and was disabled, is changed
(un-commented) and is now enabled.

I found no new problems with this test case. I believe that, at the time
that comment was written, there were bugs in Derby that have since been
repaired, and hence it is appropriate to enable this test case at this time.


git-svn-id: https://svn.apache.org/repos/asf/db/derby/code/trunk@1749069 13f79535-47bb-0310-9956-ffa450edef68