Hi, could you please share the profiling output of "TRACE select c_name,c_flux from test where c_id=**** order by c_flux desc;" and "TRACE select c_name,c_flux from test where c_id=**** order by c_flux desc limit 100;" such that we could analyse where the time is spent? Thanks, Stefan On Wed, Jun 13, 2012 at 10:38:35PM +0800, liangmeng wrote:

hi, guys, i create a simple table , and the table is up to 1 billion rows, its structure as follow: create table test(Month_ID int not null, C_NAME varchar(10) not null, C_ID int not null, MSISDN varchar(15) not null, C_FLUX double not null); and the data looks like: “201201，name1, 123213, 13723213213, 12.12321" when i execute the query "select c_name,c_flux from test where c_id=**** order by c_flux desc", it takes more than 3 minute to get the result(more than 100 thousands rows returned, if limit 100 is used, the execute time is about 40s), is there any ways to optimize? Hardwares: intel xeon 2.12*8, 32G memory, 4*1T SATA(raid 0)

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