Hi all,
I am looking for, is there any specific reason for not indexing all columns
of a table. whats the impact on the performance. Although indexing is meant
for getting great performance. So, why indexing all columns is not
feasible. (Read in docs that all columns should not be indexed
for not indexing all columns
of a table. whats the impact on the performance. Although indexing is meant
for getting great performance. So, why indexing all columns is not
feasible. (Read in docs that all columns should not be indexed)
--
Krishna Chandra Prajapati
Hi,
Following on from what Mike mentioned, indexing all columns does not
really help as MySQL will at most use one index for a query, so its
important to pick your indexes carefully and consider constructing
composite indexes. An index on a single column may not even be used
due to poor
idx_value (value)
)
On Sat, Sep 6, 2008 at 1:16 AM, ewen fortune [EMAIL PROTECTED] wrote:
Hi,
Following on from what Mike mentioned, indexing all columns does not
really help as MySQL will at most use one index for a query, so its
important to pick your indexes carefully and consider constructing
Mike mentioned, indexing all columns does not
really help as MySQL will at most use one index for a query, so its
important to pick your indexes carefully and consider constructing
composite indexes. An index on a single column may not even be used
due to poor cardinality.
Ewen
On Fri, Sep 5
default '0',
param varchar(128) NOT NULL default '',
value varchar(128) default NULL,
PRIMARY KEY (student_id,param).
KEY idx_value (value)
)
On Sat, Sep 6, 2008 at 1:16 AM, ewen fortune [EMAIL PROTECTED] wrote:
Hi,
Following on from what Mike mentioned, indexing all columns does
'',
value varchar(128) default NULL,
PRIMARY KEY (student_id,param).
KEY idx_value (value)
)
On Sat, Sep 6, 2008 at 1:16 AM, ewen fortune [EMAIL PROTECTED]
wrote:
Hi,
Following on from what Mike mentioned, indexing all columns does not
really help as MySQL will at most use
