Hi, Petr,

Thanks for the feedback.  I believe that I have located the source of
the problem -- there are a number of cases I simply neglected to
update the number of rows in the result table ;-)

Please give SVN version 443 a try when you get the chance.  Let me
know if you find anything that still needs attention.

John


On 12/9/11 2:10 AM, Thorgrin wrote:
> Hi, John
> 
> Thank you for the quick response. The problems I reported are now gone
> and I'm able to aggregate much larger data thanks to the new feature!
> 
> There is one other thing, I've noticed. When aggregating, the number
> of different rows is determined by the first part, so if the first
> part will return only two rows, and second would give me 4, when used
> together I get only the two.
> 
> Here are the commands to reproduce:
> 
> This gives two rows:
>   ibis -d ~/Downloads/bin/fi_hafo/00000000010[5] -q "SELECT
> count(*),e0id4,sum(e0id2),sum(e0id1) WHERE 1=1"
> 
> This gives four rows:
>   ibis -d ~/Downloads/bin/fi_hafo/00000000010[6] -q "SELECT
> count(*),e0id4,sum(e0id2),sum(e0id1) WHERE 1=1"
> 
> This works on both parts and gives only two rows.
>   ibis -d ~/Downloads/bin/fi_hafo/00000000010[5,6] -q "SELECT
> count(*),e0id4,sum(e0id2),sum(e0id1) WHERE 1=1"
> 
> Please find the test data at
> http://www.liberouter.org/~thorgrin/fi_hafo.tar.gz
> 
> Petr
> 
> PS.: I track the svn in git and I have made some changes so that I can
> easily create an rpm package from the library. Now I only have to run
> "git svn rebase" to get new version.
> 
> On 9 December 2011 05:42, K. John Wu <[email protected]
> <mailto:[email protected]>> wrote:
> 
>     Hi, Petr,
> 
>     Thanks for the test data and the instructions to reproduce the
>     problems.  I was able to identify two separate problems in the new
>     functions that perform aggregation-by-parts.  A update set of files
>     have been checked into the SVN repository at codeforge.lbl.gov
>     <http://codeforge.lbl.gov>.
> 
>     Please let me know if you find any additional problems.
> 
>     John
> 
>     PS: Just in case you need the information, you can check out the
>     source code with the following command
> 
>     svn checkout https://codeforge.lbl.gov/anonscm/fastbit
> 
>     Once you have a version checked out, you can simply do 'svn update' to
>     get the latest version in the repository.
> 
> 
>     On 12/8/11 8:26 AM, Thorgrin wrote:
>     > Hi John,
>     >
>     > thanks for the update, the new features looks great. Unfortunately
>     > I've bumped into some troubles with the new version.
>     >
>     > I've downloaded and compiled the latest version from svn (revision
>     > 441), I hope that is the latest one. There were no problem compiling
>     > on my machine, so the previous missing declarations of some
>     functions
>     > in mine compiler are now OK.
>     >
>     > My own app was ending in segfault on aggregation queries, so I
>     tested
>     > with the ibis tool. Need to say that I'm running the binary ibis
>     tool,
>     > not the script in examples directory, copied from the machine
>     that the
>     > library was build on.
>     > The data that can be used to reproduce the error are here:
>     >
>     > http://www.liberouter.org/~thorgrin/fi_hafo1.tar.gz
>     <http://www.liberouter.org/%7Ethorgrin/fi_hafo1.tar.gz>
>     >
>     > the command is:
>     > ibis -d ./fi_hafo1/00000000000[1,5] -q "SELECT
>     > count(*),e0id4,sum(e0id2) WHERE 1=1"
>     >
>     > You will notice that this does not indicate any error but does not
>     > produce any table line either. Previous version always prints at
>     least
>     > one line (more on verbose). My app ends in segfault after it
>     finishes
>     > the query and tries to read from the result table, so I believe
>     it is
>     > the same problem and ibis only reads differently.
>     >
>     > In attachement are two logs using -v 10, one for version 1.2.4
>     (which
>     > is really svn build 436 or so), one for 1.2.5. Both has
>     extension .out.
>     >
>     > When I modify the query only a bit, i get segfault from the ibis
>     tool.
>     > The command is:
>     > ibis -d ~/Documents/devel/data/fi_hafo1/00000000000[1,5] -q "SELECT
>     > count(*),e0id4,sum(e0id2),sum(e0id1) WHERE 1=1"
>     >
>     > The valgrind output can be found in file ibis1.2.5.segfault.
>     >
>     > It is entirely possible that something is amis on my part, if
>     you have
>     > any idea what might that be, please let me know. Also if you
>     need any
>     > other output or information, just let me know.
>     >
>     > Petr Velan
>     >
>     >
>     > On 8 December 2011 00:19, K. John Wu <[email protected]
>     <mailto:[email protected]>
>     > <mailto:[email protected] <mailto:[email protected]>>> wrote:
>     >
>     >     Hi, Everyone,
>     >
>     >     Thanks for all the input on the memory usage issues.  There is a
>     >     updated version of FastBit source code marked as ibis1.2.5
>     with some
>     >     initial implementation of aggregation operations by parts.  This
>     >     should reduce the memory usage for aggregation operations
>     that does
>     >     not require all the data to be in memory.
>     >
>     >     The new version is available at
>     >    
>     http://codeforge.lbl.gov/project/showfiles.php?group_id=44&release_id=329
>     
> <http://codeforge.lbl.gov/project/showfiles.php?group_id=44&release_id=329>
>     >    
>     <http://codeforge.lbl.gov/project/showfiles.php?group_id=44&release_id=329
>     
> <http://codeforge.lbl.gov/project/showfiles.php?group_id=44&release_id=329>>
>     >
>     >     We have also included two patches from Jon Strabala
>     >     and Robert Wong to address a couple of different
>     >     issues.
>     >
>     >     This release also fixes a number issues raised by
>     >     Alexandre Maure, Anderson Carniel, Jon Strabal,
>     >     Andrew Olson, Teryl Taylor, Robert Wong, and
>     >     others.
>     >
>     >     Please feel free to let us know if you encounter any
>     problems with the
>     >     new source code.
>     >
>     >     John
>     >
>     >     PS: Just in case you are wondering about which aggregations
>     can be
>     >     performed by parts.  The aggregation operators, count, sum,
>     min, and
>     >     max can be performed by parts.  The operators, avg, var, and
>     stddev
>     >     can be transformed into sums and counts and are currently
>     internally
>     >     transformed into sums and counts.  This transformation may
>     introduce
>     >     very slightly different results.  The computations are done with
>     >     double-precision floating-point numbers, which have 16-digit
>     >     precision.  The difference should be limited to the last
>     couple of
>     >     digits and should not be noticeable for most users.
>      However, those
>     >     users with very sensitive computations should know that the
>     converted
>     >     expression have different round-off properties from the original
>     >     expression.  The bad operations are distinct and median,
>     both which
>     >     require all data to be in memory.
>     >
>     >     PPS: We have made some progress in supporting joins through
>     a new
>     >     class called quaere.  We intend to eventually rename it to
>     >     ibis::query.
>     >     _______________________________________________
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>     >     [email protected]
>     <mailto:[email protected]>
>     <mailto:[email protected]
>     <mailto:[email protected]>>
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>     >
>     >
>     >
>     >
>     > _______________________________________________
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> 
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