Yes, but the optimizer doesn't know that. -----Original Message----- From: vegiv...@gmail.com [mailto:vegiv...@gmail.com] On Behalf Of Johan De Meersman Sent: Wednesday, March 03, 2010 6:16 AM To: Zardosht Kasheff Cc: Jonas Oreland; mysql@lists.mysql.com Subject: Re: Re bug#45458
Unless I'm very much mistaken, InnoDB tables always have a clustered index as their primary key. On Wed, Mar 3, 2010 at 2:58 PM, Zardosht Kasheff <zardo...@gmail.com> wrote: > Hello Jonas, > > Thank you for filing this feature request. Are there plans to add > support for clustered indexes in MySQL soon? This is something I have > been researching on and off for a while now. Here are my thoughts. > > It seems that there are two parts to this feature request: > 1) a new flag that allows the storage engine to report that an index > is clustered > 2) changes to the optimizer to properly support clustered keys. > > I like #1. The way that I dealt with it was not as good. I added > handler::supports_clustered_keys(), and used that function and > HA_CLUSTERING from my patch to determine if an index is clustered. > Your method is better. > > As for #2, I do not think it is enough. Here are two other locations > of code I know that will need to be modified: > 1) find_shortest_key in sql/sql_select.cc. (This will be an addition > to MySQL bug #39653) > 2) get_best_ror_intersect in sql/opt_range.cc. This is for > index_merge. A patch of what I have done is in the attached file > 9-index_merge_clustering.txt. This patch was the result of a long > thread on the internals alias (which you may want to CC for this > discussion). The link to the thread is > http://lists.mysql.com/internals/36977. > > There may be more places that need to be modified. I think the > approach to finding out if other places need to be modified is to > pattern match off of how the optimizer deals with clustered v. > non-clustered primary keys. It does so by having a function > handler::primary_key_is_clustered. I think one needs to search the > optimizer for all instances of this function, see why it is being > called, and see if it applies to clustered v. non-clustered secondary > keys as well. > > -Zardosht > > On Wed, Mar 3, 2010 at 5:57 AM, Jonas Oreland <jo...@mysql.com> wrote: > > Hi, > > > > I just filed http://bugs.mysql.com/bug.php?id=51687 > > which is very related to your bug#45458. > > > > If you would care to look at it and provide feedback, > > I would appreciate it. > > > > /Jonas > > > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/mysql?unsub=vegiv...@tuxera.be > -- Bier met grenadyn Is als mosterd by den wyn Sy die't drinkt, is eene kwezel Hy die't drinkt, is ras een ezel This message contains confidential information and is intended only for the individual named. If you are not the named addressee, you are notified that reviewing, disseminating, disclosing, copying or distributing this e-mail is strictly prohibited. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any loss or damage caused by viruses or errors or omissions in the contents of this message, which arise as a result of e-mail transmission. [FriendFinder Networks, Inc., 220 Humbolt court, Sunnyvale, CA 94089, USA, FriendFinder.com -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
