I believe the optimizer does know that InnoDB has a clustered primary key, because ha_innobase::primary_key_is_clustered returns true
On Wed, Mar 3, 2010 at 2:22 PM, Gavin Towey <gto...@ffn.com> wrote: > 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=zardo...@gmail.com > > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
