SQL Server: Populate (Minute) Date Dimension table -


i'm working on script populate simple date dimension table granularity down minute level. table should contain smalldatetime representing every minute 1/1/2000 12/31/2015 23:59.

here definition table:

create table [dbo].[ref_minutedimension] (     [timestamp] smalldatetime not null,     constraint [pk_ref_minutedimension] primary key clustered ([timestamp] asc) (fillfactor = 100) );

here latest revision of script:

declare @currenttimestamp smalldatetime; select top(1) @currenttimestamp = max([timestamp]) [dbo].[ref_minutedimension];  if @currenttimestamp not null     set @currenttimestamp = dateadd(minute, 1, @currenttimestamp); else     set @currenttimestamp = '1/1/2000 00:00';  alter table [dbo].[ref_minutedimension] drop constraint [pk_ref_minutedimension];  while @currenttimestamp < '12/31/2050 23:59' begin      ;with dateindex ([timestamp])     (         select @currenttimestamp         union         select dateadd(minute, 1, [timestamp]) dateindex di di.[timestamp] < dbo.fgetyearend(@currenttimestamp)     )     insert [dbo].[ref_minutedimension] ([timestamp])         select di.[timestamp] dateindex di     option (maxrecursion 0);      set @currenttimestamp = dateadd(year, 1, dbo.fgetyearbegin(@currenttimestamp))  end  alter table [dbo].[ref_minutedimension] add constraint [pk_ref_minutedimension] primary key clustered ([timestamp] asc) (fillfactor = 100);

a couple of things point out:

  • i've added logic drop , subsequently re-add primary key constraint on table, hoping boost performance.
  • i've added logic chunk inserts yearly batches minimize impact on transaction log. on side note, we're using simple recovery model.

performance so-so , takes around 15-20 minutes complete. hints/suggestions on how script "tuned up" or improved?

also, completeness here fgetyearbegin , fgetyearend:

create function dbo.fgetyearbegin (     @dtconvertdate datetime ) returns smalldatetime begin     return dateadd(year, datediff(year, 0, @dtconvertdate), 0)  end   create function dbo.fgetyearend (     @dtconvertdate datetime ) returns smalldatetime begin     return dateadd(minute, -1, dateadd(year, 1, dbo.fgetyearbegin(@dtconvertdate))) end

this takes 11 seconds on server...

if      object_id('tempdb..#somenumbers') not null drop table #somenumbers; create  table #somenumbers (id int);  declare @minutes int,         @days int;  select  @minutes = datediff(minute,'1/1/2000 00:00','1/2/2000 00:00'),         @days = datediff(day,'1/1/2000 00:00','1/1/2051 00:00');     base (                select  1 seedid         union           select  1 ),      build (         select  seedid            base         union           select  b.seedid + 1            build b         cross   join base b2           b.seedid < 14 ) insert  #somenumbers select  row_number() on (order seedid) id    build option (maxrecursion 0);  if      object_id('tempdb..#values') not null drop table #values; create  table #values ([timestamp] smalldatetime not null);     dates (         select  dateadd(day,id-1,'1/1/2000 00:00') [timestamp]            #somenumbers           id <= @days ) insert  #values select  convert(smalldatetime,dateadd(minute,id-1,[timestamp]))    dates d join    #somenumbers sn         on  sn.id <= @minutes order   1

Comments

  1. Unknown27 August 2018 at 05:45

    This comment has been removed by the author.

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  2. Unknown27 August 2018 at 05:46

    can you explain you code which is taking 11 sec ?

    ReplyDelete

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