sql server - How to improve SQL query performance (correlated subqueries)? -

-

i write below query in better & efficient way help?

select   a.assetnum asset,          a.assettag asset_tag,          a.manufacturer manufacturer,          a.serialnum serial,          a.description description,          (              select case  a.isrunning                     when  1                       'operational'                      when  0                       'down'                      end          )  condition ,          l.kbs_loctag location,          (              select top 1 wo.wonum                 workorder wo                wo.assetnum = a.assetnum                     , wo.worktype = 'un'              order wo.reportdate desc          ) last_workorder,          (              select wo.statusdate                 workorder wo                wo.wonum in                     (                         select   top 1 wo.wonum                              workorder wo                            wo.assetnum = a.assetnum                                  , wo.worktype = 'un'                         order wo.reportdate desc                     )          ) last_status_date,          (              select top 1 lt.memo                labtrans lt               lt.assetnum = a.assetnum                      , lt.transtype = 'repair'              order lt.transdate desc        ) action   asset         left outer join locations l            on a.location = l.location  (            a.description '%wash%'             or a.description '%dryer%'        ) order  l.location,         a.description

in cases prefer use apply operator instead of correlated subquery.

in case suggest next solution:

select   a.assetnum asset,          a.assettag asset_tag,          a.manufacturer manufacturer,          a.serialnum serial,          a.description description,          case  a.isrunning              when  1  'operational'               when  0  'down'           end  condition,          l.kbs_loctag location,          wo.wonum last_workorder,          wo.statusdate last_status_date,          lt.memo action   asset         left outer join locations l on a.location = l.location        outer apply (              select top 1 wonum, statusdate                workorder                assetnum = a.assetnum                     , worktype = 'un'              order reportdate desc) wo        outer apply (              select top 1 memo                labtrans               assetnum = a.assetnum                      , transtype = 'repair'              order transdate desc) lt   (            a.description '%wash%'             or a.description '%dryer%'        ) order  l.location, a.[description]

btw - can find amazing video lesson (from itzik ben-gan)about using apply operator here.


Comments

Post a Comment

Popular posts from this blog

css - Which browser returns the correct result for getBoundingClientRect of an SVG element? -

-
this svg contains rect overflows svg element: <svg id='svg' width='10' height='10'> <rect x='-10' y='-10' width='30' height='30'/> </svg> chrome 28 , opera 12 return getboundingclientrect() svg element width , height of 10. firefox 23 reports width , height of 30. correct? jsfiddle the relevant spec cssom , delegates svg spec if svg element not "have associated css layout box". haven't found definition of "having associated css layout box", correct result seem hinge on definition, getbbox returns 30x30 rect in browsers. this firefox bug fixed now, fix in firefox nightlies , should make through firefox 33 released on 14 october 2014. see bug 530985 details.
Read more

gcc - Calling fftR4() in c from assembly -

-
i trying asm fft implementation www.embeddedsignals.com work. running make gives error: undefined reference fftr4(short*, short*, int) at top of asm have .syntax unified .thumb .global fftr4 .type fftr4, %function and there #define's associate c functions arguments registers followed macros fftr4 function uses. after that, fftr4 called .thumb_func fftr4: stmfd sp!, {r4-r11, lr} mov tmp0, #0 // bit reversed counter mov tmp1, #0 .word 0xf3a2fa92 //rbit r3,r2 //rbit r,n lsl r,#3 and c code follows: void fftr4(short *y, short *x, int n); short x[512]; short y[512]; int i; void loop() { (i=0;i<512;i++) x[i]=0; (i=0;i<512;i=i+8) { x[i+0]=16384; x[i+2]=16384; x[i+4]=-16384; x[i+6]=-16384;} fftr4(y, x, 256); serialusb.println(y[128]); serialusb.println(y[129]); serialusb.println(y[384]); serialusb.println(y[385]); // expected results: //y[128]is 8191; y[129] -8190 y[
Read more

Function that returns a formatted array in VBA -

-
i have function prints excel data text file in array format following: [ ['id', 'label', 'longitude', 'latitude', 'country', 'region', 'ttl_wt_flw_thru', 'sum-of-bol-wt', 'count of wdr_ref', 'ratio'], ['aeauh', 'abu dhabi, united arab emirates', 54.3666667, 24.4666667, 'ae', 'eame', 66, 30, 8432, 281.066666666667], ['aedxb', 'dubai, united arab emirates', 55.307485, 25.271139, 'ae', 'eame', 682, 3, 8369, 2789.66666666667] ] my code writing array is: function fillsourcearray() dim long, j long, s string dim lastrow double dim s1 string 'opens file filepath = filepath & "dataarray" & ".txt" open filepath output #1 'read source data dataarray = sheets("nodes").cells(1).currentregion.value 'determine lastrow lastrow = sheets("nodes").range
Read more