On Sat, Feb 01, 2003 at 04:44:00PM +0100, Erik Moeller wrote:
Adding composite indexes won't help there. What you need is an extra redundant table that contains the number of wanted links.
We have a table that contains broken links, which is used in the Most Wanted query.
I know. I was the one who originally introduced that table. :-)
I have no information about the size of these tables in our current database, but I suspect that, again, indexes are not properly used, otherwise the bad performance of this query (which has prompted Magnus to cache the whole page and Brion to create a "miser" mode in which it cannot be loaded) is not explainable.
I can assure you that the indices are well-defined there and used in the proper way. Some queries are simply hard to compute and can only be improved by precomputing stuff in redundant tables.
HANDLER works almost exactly the same as SELECT from a syntax POV.
That's only part of the problem. If anyone wants to mess with this they have to understand what it does and why. That doesn't go away if you have similar syntaxes.
I think your arguments against HANDLER are misguided. We clearly have situations where we do not nead consistent reads, and in these situations, HANDLER may be a great help. As I said, we can abstract the functionality to reduce complexity.
As I said, syntactically hiding the complexity doesn't make it go away.
They are currently labeling it as a "gamma". I think it might be worth giving a try, we can always downgrade if it creates problems.
Not if we start using MySQL4 stuff and the problems only start to appear after a while. I agree that the risc is very small, but still.
How about using it on meta only? It is reasonably active, but not mission critical.
Good idea, but I assumed that Brion was going to test it on the test server anyway.
I have done tests on the link lookup with a local database and it's very slow with link-heavy pages. This is also what our profiling has shown.
Could you be a bit more specific about that?
see http://www.wikipedia.org/pipermail/wikitech-l/2002-November/001166.html http://www.wikipedia.org/pipermail/wikitech-l/2003-January/002238.html
Ok. I commented already on that in my other mail. Btw. did you see Lee's original comments in linkcache.doc in /docs on why the caching is done the way it is done?
-- Jan Hidders
.---------------------------------------------------------------------. | Post-doctoral researcher e-mail: jan.hidders@ua.ac.be | | Dept. Math. & Computer Science tel: (+32) 3 820 2427 | | University of Antwerp, room J1.06 fax: (+32) 3 820 2421 | | (UIA) Universiteitsplein 1, B-2610 Wilrijk - Antwerpen (Belgium) | `---------------------------------------------------------------------'