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From:<imre Date:October 27 2006 6:10am
Subject:RE: Speed of DECIMAL
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> From: Jerry Schwartz [mailto:jschwartz@stripped] 
> 
> What is going slower, INSERT / UPDATES or SELECTS?

Complex SELECTs

> CHAR should make for quite efficient processing, since to a 
> large degree nobody cares what's in there: it just slams the 
> data in, or does a simple byte-by-byte comparison. There is 
> probably hardware support for that kind of operation. Decimal 
> arithmetic, on the other hand, requires more data 
> manipulations. The size of the column probably is outweighed 
> by the more complex data handling.

I am doing the following operations:

- Joins based on indexed columns
- Division by power of 10
- Substring
- LIKE comparisons in the form of  decimal_column LIKE 'number%'

Is any of these especially slow decimals?
How would they work with BIGINT(15) UNSIGNED ZEROFILL?
 
> No doubt someone whose internals experience is more recent 
> than mine will chime in.
> 
> Regards,
> 
> Jerry Schwartz
> Global Information Incorporated
> 195 Farmington Ave.
> Farmington, CT 06032
> 
> 860.674.8796 / FAX: 860.674.8341
> 
> 
> > -----Original Message-----
> > From: imre@stripped [mailto:imre@stripped]
> > Sent: Thursday, October 26, 2006 4:37 AM
> > To: mysql@stripped
> > Subject: Speed of DECIMAL
> >
> > Hi,
> >
> > I was hoping to speed up my database operations a bit  by changing 
> > some colums in my database from CHAR(15) ASCII to DEC(15) UNSIGNED 
> > ZEROFILL.  I was expecting a speedup as DEC(15) is more 
> compact, and 
> > this columns are also part of InnoDB indices.  In contrary to my 
> > expectations, running my test suit took approximately three 
> times as 
> > much time, as before.
> >
> > Could anybody give me a probable reason for this slowdown?
> >
> > Thx
> >
> > ImRe
> >
> > P.S.: Ver 5.0.24a
> >
> >
> >
> > --
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> >
> >
> 
> 
> 
> 
> 
> 


Thread
Speed of DECIMALimre26 Oct
Re: Speed of DECIMALBrent Baisley26 Oct
RE: Speed of DECIMALJerry Schwartz26 Oct
  • RE: Speed of DECIMALimre27 Oct
Re: Speed of DECIMALChris27 Oct
  • Re: Re: Speed of DECIMALDan Buettner27 Oct
Re: Speed of DECIMALChris27 Oct
RE: Speed of DECIMALJerry Schwartz27 Oct