Re: 9.2.4: Strange behavior when wildcard is on left side of search string

This doesn't seem either buggy or strange...

An index on the ordering of that column is not helpful in handling a
leading wildcard, and so the query optimizer will, in such cases, revert,
correctly, to using a sequential scan and filtering the results.

If you have cases where this sort of wildcard needs to be fast, a
functional index could help.

Create index foo on tbl (reverse(col));

And reverse the wildcard so the index is usable:

Select * from tbl where reverse(col) like 'esrever%';

That query can harness the reversed index.

Unfortunately, no ordered index helps with

Select * from too where col like '%something%';

For that, a full text search index can help, but that is a longer story.

At any rate, what you are observing is no surprise, and consistent with
what many database systems do.