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  1. WiredTiger
  2. WT-266

__wt_schema_open_index doesn't correct for schema sort changes

    • Type: Icon: Task Task
    • Resolution: Done
    • WT1.3
    • Affects Version/s: None
    • Component/s: None

      Michael, I re-wrote __wt_schema_open_index() to set a cursor at "index:[table-name]:" instead of reading through the entire schema file, and I noticed this chunk of code:

          295                 if ((size_t)i * sizeof(const char *) >= table->idx_name_alloc)
          296                         WT_ERR(__wt_realloc(session, &table->idx_name_alloc,
          297                             WT_MAX(10 * sizeof(const char *),
          298                             2 * table->idx_name_alloc), &table->idx_name));
          300                 if (table->idx_name[i] == NULL)
          301                         WT_ERR(__wt_strdup(session, uri, &table->idx_name[i]));

      Specifically, the test for table->idx_name[i] already being set bothers me.

      If you open the indices, and then create a new index that sorts in the middle of the existing indices, the indices won't be in the same order, and so table->idx_name[i] won't be NULL, but it won't be the right name, either. It's pretty easy to make it happen, this test script gets it to fire for me:

      import wiredtiger, wttest
      class test_f(wttest.WiredTigerTestCase):
          # This test drops core.
          def test_f(self):
              uri = "table:xxx"
      	    'key_format=i,value_format=SiS,' +
      	indxname = 'index:' + uri.split(":")[1]
      	self.session.create(indxname + ':indx1', 'columns=(column2)')
      	self.session.create(indxname + ':indx3', 'columns=(column4)')
      	self.session.truncate(uri, None, None, None)
      	self.session.create(indxname + ':indx2', 'columns=(column3)')
      	self.session.truncate(uri, None, None, None)
      	self.session.drop(uri, None)
      if __name__ == '__main__':

      I was thinking the simplest fix would be have an interior loop that steps through the list of indices looking for a matching index name, and if it doesn't find one, it allocates new space. But that's N*2 in the number of indices the table has, would we care?

      Anyway, me know if this needs fixing and how you'd like it fixed, and I'll make it happen.

            michael.cahill@mongodb.com Michael Cahill (Inactive)
            keith.bostic@mongodb.com Keith Bostic (Inactive)
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