On Mar 14, 2004, at 17:50, Ivo Köthnig wrote:
I played a little bit with the (german) old_table
(from 20040305) and
have
some questions about it.
1. As I understand the first entry of each row, this is an id,
incremented for
each new row. since there are missing some of the numbers, I assume
that this
are rows, which was deleted. Is this right?
Correct.
2. There is a column timestamp and a column inverse
timestamp. For
what reason
we need the inverse timestamp?
MySQL 3.x is unable to optimize a descending sort using a column index.
Adding an inverted column to index on dramatically sped up various
features such as page history and user contributions lists as the wikis
continued to grow in size.
On MySQL 4.x this is unnecessary, and we may remove the column from the
next major revision.
There also seems to be an inconsistency. The entry
with the id 494209
(article
about "Optik" in namespace 0 has timestamp "20031231041409" but
inverse
timestamp "80008783828360". May this is a new-year-bug? May this
should be
corrected manually?!
There was an old bug in page move that didn't properly update
inverse_timestamp. If you see any others incorrect, please make a list
and we'll fix them all...
Additionally, that inverse_timestamp is for the year 1999... there was
a very brief problem at one point where one of the web servers came up
with a dramatically incorrect clock setting and corrupted a number of
articles' dates. That may be an artifact of that incident.
3. Which namespace is represented by which of the
numbers 0 till 9?
0: (article)
2: User:
4: Wikipedia:
6: Image:
8: MediaWiki:
The odd numbers are for the associated talk/discussion namespaces.
4. The column for the "user-comment" in the
begining contains often
'*' but
later nothing. Was it just the behaviour of the old software to
represent no
comment by '*'?
Yes, UseModWiki puts a "*" as the default comment in the edit form.
5. The column for the "user_id" in the
beginning contains just 0, even
for
well-known users. later (after conversion_script appears) the correct
id is
printed.
The conversion from UseModWiki is unable to set up user accounts, since
the mechanism for this is wildly different on UseMod than on MediaWiki.
Pre-conversion edits are thus marked without a user_id.
(UseModWiki records _sets of preferences_, not really user accounts.
Multiple "user id"s may have the same username, and there's no
authentication for the use of names.)
The column for the "user_name" has the same
strange behaviour. It
contains dns-names instead of IP-adresses. Was this the behaviour of
the old
software?
Yes.
6. The coulumn "old_flags" seems to contain
nothing. (its almost
always empty,
but contains one/sometimes '0'). Whats the application of this column?
What
flags does it contain?
For a long time it was totally unused. Now it may contain "gzip" if
that revision's text is stored compressed; currently this is used only
on the English Wikipedia on a semi-experimental basis.
-- brion vibber (brion @
pobox.com)