[Tuesday, July 31, 16:55] > I have been working on midterm from the Tuesday Session of INFSCI 2711 > Fall 199. I had some questions I was hoping you could clarify for me. > > 1) On qustion 5a, I was wondering if a TABLE_NAME from tabs could be > joined to a SEGMENT_NAME in USER_EXTENTS? I know that each table > generally has one segment, and I see that when you asked for the table > name that your solution selects the SEGMENT_NAME, but technically I am not > sure if these two values are the same. My solution looks like your first > sample solution, except I would like to select TABLE_NAME from TABS and > then join TABS to USER_SEGMENTS via TABLE_NAME and SEGMENT_NAME. I think there is no other way than to use SEGMENT_NAME = TABLE_NAME. I tried select * from dict_columns where column_name = 'SEGMENT_NAME'; None of the 8 tables that contain a column called SEGMENT_NAME also contain a column TABLE_NAME. It is important to require SEGMENT_TYPE = 'TABLE' when selecting a segment since there can be an index and a table with the same name, resulting in two segments with the same name. It is true that the first solution would not quite work with a partitioned table. It would have several segments with the same name and type, separated only by the partition name. > 2) For question 4b, I am confused about where the 50,000 rows (on page 8) > and the 4,750,000 bytes comes from. Previously, I thought the question > said there were 100,000 rows and I would expect that 49 bytes x 100,000 > rows would yield 4,900,000 bytes to store the rows. Am I messing > something up here? The 50,000 rows result from assuming that half of the rows have the Oscars column set, the other have it null. 4,750,000 = 46 Bytes * 50,000 (rows with Oscar=null) + 49 Bytes * 50,000 By the way, I now the computation that is listed under "It is also acceptable". If the rows are quite long, some space remains unused because each block contains only complete rows, not pieces. This rounding is not done quite correct if one first computes the required bytes and then how many blocks this means.