Re: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Dan Nelson
In the last episode (Nov 19), Benjamin Pflugmann said: > On Mon 2002-11-18 at 19:01:57 -0500, [EMAIL PROTECTED] wrote: > [...] > > A BITMAP index will work efficiently in this case, no matter what > > the distribution of the keys is. The only requirement is that the > > column be low-cardinality.

Re: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Benjamin Pflugmann
Hi. On Mon 2002-11-18 at 19:01:57 -0500, [EMAIL PROTECTED] wrote: [...] > A BITMAP index will work efficiently in this case, no matter what the > distribution of the keys is. The only requirement is that the column be > low-cardinality. > > It basically works like this: > > true 01101 > f

Re: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Daniel Koch
On Mon, 2002-11-18 at 16:22, Michael T. Babcock wrote: > Neulinger, Nathan wrote: > > >It's actually relatively speedy WITH the bad index, but maintaining that > >index (given it's lopsided nature) is very expensive. > > > >Yes, the point is to ONLY index the row if it matches the restriction. >

Re: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Michael T. Babcock
Neulinger, Nathan wrote: It's actually relatively speedy WITH the bad index, but maintaining that index (given it's lopsided nature) is very expensive. Yes, the point is to ONLY index the row if it matches the restriction. To clarify, if MySQL is indexing a binary value with lopsided distr

Re: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Jeremy Zawodny
On Tue, Nov 19, 2002 at 07:12:27AM +1100, Dean Harding wrote: > Actually, it's a slightly different problem - a very uneven distribution > of values on a column, not a small number of possible values like a > bitmap index is for. Exactly. > In my opinion, this is a pretty useless feature, I mean

RE: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Neulinger, Nathan
1 Computing Services Fax: (573) 341-4216 > -Original Message- > From: Dean Harding [mailto:[EMAIL PROTECTED]] > Sent: Monday, November 18, 2002 2:12 PM > To: 'Daniel Koch'; [EMAIL PROTECTED] > Cc: 'Egor Egorov'; Neulinger, Nat

RE: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Dean Harding
] > Sent: Tuesday, 19 November 2002 5:58 am > To: [EMAIL PROTECTED] > Cc: Egor Egorov; Neulinger, Nathan; Jeremy Zawodny > Subject: Re: feature suggestion - indexes with "where" clause or similar > > On Mon, 2002-11-18 at 12:29, Jeremy Zawodny wrote: > > > >

Re: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Daniel Koch
On Mon, 2002-11-18 at 12:29, Jeremy Zawodny wrote: > > If I've got you right status can have values 0 or 1. In this case > > you can just use " SELECT ... WHERE status=1 .." (index wil be used) > > or "SELECT .. WHERE status=0 .." (index will not be used, because > > scan the whole table will be f

Re: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Jeremy Zawodny
On Mon, Nov 18, 2002 at 05:38:00PM +0200, Egor Egorov wrote: > Neulinger, > Friday, November 15, 2002, 7:25:27 PM, you wrote: > > NN> Assume I have a mysql table (myisam most likely) with a few hundred > NN> thousand rows in it. One of the columns indicates success or failure. > NN> 99.9% of the r

re: feature suggestion - indexes with "where" clause or similar

2002-11-18 Thread Egor Egorov
Neulinger, Friday, November 15, 2002, 7:25:27 PM, you wrote: NN> Assume I have a mysql table (myisam most likely) with a few hundred NN> thousand rows in it. One of the columns indicates success or failure. NN> 99.9% of the rows will have "0" in that column. But a small number will NN> have 1. I n

RE: Feature suggestion

2001-08-28 Thread Simon Green
See V 4 -Original Message- From: Alexander Barkov [mailto:[EMAIL PROTECTED]] Sent: 28 August 2001 14:13 To: [EMAIL PROTECTED] Subject: Feature suggestion Hello! Currently replication is implemented between two mysqld. I would like to suggest new feature. Make it possible for two mysq