Just in case you need some more information about how to fix your queries,
this walks you through some examples
http://hackmysql.com/case2
On Mon, Mar 22, 2010 at 10:00 AM, Nicholas Hart wrote:
> I am looking to analyze and speed up some of my queries by adding any
> necessary indexes. Is there
On Mar 23, 2010, at 11:50 AM, Daniel Convissor wrote:
> On Tue, Mar 23, 2010 at 11:12:57AM -0400, Rob Marscher wrote:
>>
>> I'm having trouble finding exactly where it says it.
> ...
>> If you run EXPLAIN, you'll see it only picks one index to use for each
>> table.
>
> That may be true for the
On Tue, Mar 23, 2010 at 11:12:57AM -0400, Rob Marscher wrote:
>
> I'm having trouble finding exactly where it says it.
...
> If you run EXPLAIN, you'll see it only picks one index to use for each
> table.
That may be true for the queries you ran. If that's the case, you don't
have enough rows
> > One caveat to this is that mysql will only use one index per table in
> > your query.
>
> I've never heard that before. Do you have a citation from the manual on
> MySQL's website, please?
It's thrown around through some of the links Rob mentioned, but it's true
and notorious issue with inde
On Mar 23, 2010, at 10:16 AM, Daniel Convissor wrote:
> On Mon, Mar 22, 2010 at 01:42:14PM -0400, Rob Marscher wrote:
>>
>> One caveat to this is that mysql will only use one index per table in
>> your query.
>
> I've never heard that before. Do you have a citation from the manual on
> MySQL's
On Mon, Mar 22, 2010 at 01:42:14PM -0400, Rob Marscher wrote:
>
> One caveat to this is that mysql will only use one index per table in
> your query.
I've never heard that before. Do you have a citation from the manual on
MySQL's website, please?
Thanks,
--Dan
--
T H E A N A L Y S I S
Hi Nick:
> $sql = "select dt1.*, d.* from
> driver d join
> (select `driver`, date(`leave`), sum(`points`) as pnts,
> sum(`xpnts`) as xpnts from check_head
> where date(`leave`) = '".$sdate."'
> group by `driver`) dt1
> on dt1.driver = d.id_num w
On Mar 22, 2010, at 1:31 PM, John Campbell wrote:
...snip...
> 1: add an index on the timestamp 'leave'
...snip...
> This is because mysql never uses indexes when a function is on the
> left hand side.
> There is no "formula" to follow, but you need to intuitively
> understand how relational datab
On Mon, Mar 22, 2010 at 11:00 AM, Nicholas Hart
wrote:
> For example:
> $sql = "select dt1.*, d.* from
> driver d join
> (select `driver`, date(`leave`), sum(`points`) as pnts,
> sum(`xpnts`) as xpnts from check_head
> where date(`leave`) = '".$sdate."'
>
In addition to what others said...
There is a lot more instruction both online and offline, but here is a brief
example illustrating EXPLAIN:
http://www.experts-exchange.com/articles/Database/MySQL/3-Ways-to-Speed-Up-MySQL.html
The docs can be a bit dense if you're not familiar with what you are
On Mar 22, 2010, at 11:00 AM, Nicholas Hart wrote:
> I am looking to analyze and speed up some of my queries by adding any
> necessary indexes. Is there a formula to follow in adding indexes to
> multiple join queries? I have made some attempts using explain but am not
> sure I understand it a
It depends on where the join is occurring. If you have a HABTM
relationship between the join tables then a index should be added to the
pivot table. If not then I would assume that the column you are joining
on would be a candidate for an index. Do these tables have a PRIMARY
KEY already est
I am looking to analyze and speed up some of my queries by adding any
necessary indexes. Is there a formula to follow in adding indexes to
multiple join queries? I have made some attempts using explain but am not
sure I understand it all that well.
For example:
$sql = "select dt1.*, d.* from
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