Re: Why does mysql drop index very very slow in a large table?

1) create table T1 like T; This creates an empty table T1 with indexes ndx1,ndx2,ndx3 and ndx4. 2) alter table T1 drop index ndx3; This drops index ndx3 on the empty T1, which should be instantaneous. 3) insert into T1 select * from T; This will populate table T and load all three(3) indexes for

Why does mysql drop index very very slow in a large table?

Why does mysql drop index very very slow in a large table? I have a large table with more than 5M rows, and many indexes. Now I want to drop some of them. But it seems that mysql can not handle this very well. It takes a very long time (more than half an hour) to do , and make me unbearable. And

Re: How to speed up query of indexed column with 5M rows?

+---++-+--+-+---+-+--++--++-+ | Table | Non_unique | Key_name| Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | +-

How to speed up query of indexed column with 5M rows?

How to speed up query of indexed column with 5M rows? I have a table with more than 5M rows. (400M .MYD 430M .MYI). It took 27 seconds to do a common select...where... in the index column. I can not bear the long run. Vmstat show that system was bounded by IO busy.(Always more than 13000 bi/s,

subquery hanging

I'm not an SQL expert and have a subquery problem. I have a query that consists of a query inside of a query inside of a query. The two inner subqueries work fine together and give me a list of "ids" for matching records. And they do it very quickly. If I then take their results and feed them to th

where do you hide the temp files?

from table handler) and am basically stuck. Hope I've given enough info. Thanks for all your help, K -- Kay Bowen Tec-Masters, Inc. Advanced Studies and Research Center - Before posting, please check:

RE: Join problem, I think

; table. A bit of a warning here... if there is no match, then the "NULL" value is inserted into that spot. Hope it helps, K -- Kay Bowen Tec-Masters, Inc. Advanced Studies and Research Center - Before

select field(3)

. The program I am looking to develop would require MANY queries that 'describe table_name' to get the field names associated with the positions in the table. If this can't be done, then so be it. It would just save me a very large h

Todd Poole

Please remove him from this list. I am the Exchange Admin at MindLeaders. He no longer works here. Dave Bowen MIS Supervisor MCSE Phone: (614) 880-1605 Fax: (614) 340-6540 mailto:[EMAIL PROTECTED] MindLeaders (www.mindleaders.com