Hi,
I have fucntion in my code which writes variable length data to HDF5 file.
I have a dataset created as,
fileType = H5Tvlen_create(H5T_NATIVE_UCHAR)
'DataSpace' with Rank: 1 and Dims: 1;
And chunking enabled for the same.
A function writing a data to this dataset, is being called in loop.
Before writing to a dataset I extend the dimensions of the dataset as well.
Till here, everything goes correct. i.e. I'm able to extend dataset with
this data type successfully.
But, when I call,
H5Dwrite (dset, memtype, memspace, filespace, H5P_DEFAULT,wdata);
CPU usage goes 100%.
Is it a normal behaviour that the H5DWrite API take such a huge part of CPU
to write variable length of data?
···
-----
Best Regards,
Santosh
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Santosh,
Similar performance issue was reported on this list in the past
(see http://hdf-forum.184993.n3.nabble.com/Variable-length-types-slowness-td195101.html#a195101)
The fix is scheduled for 1.8.7 (May 2011), but we will let everyone on this list know when it becomes available in a snapshot (hopefully before Thanksgiving if things go according to the plan 
Thank you!
Elena
···
~~~~~~~~~~~~~~~~~~~~~
Elena Pourmal
The HDF Group
epourmal@hdfgroup.org
~~~~~~~~~~~~~~~~~~~~~
On Oct 11, 2010, at 12:04 AM, santoshdarekar wrote:
Hi,
I have fucntion in my code which writes variable length data to HDF5 file.
I have a dataset created as,
fileType = H5Tvlen_create(H5T_NATIVE_UCHAR)
'DataSpace' with Rank: 1 and Dims: 1;
And chunking enabled for the same.
A function writing a data to this dataset, is being called in loop.
Before writing to a dataset I extend the dimensions of the dataset as well.
Till here, everything goes correct. i.e. I'm able to extend dataset with
this data type successfully.
But, when I call,
H5Dwrite (dset, memtype, memspace, filespace, H5P_DEFAULT,wdata);
CPU usage goes 100%.
Is it a normal behaviour that the H5DWrite API take such a huge part of CPU
to write variable length of data?
-----
Best Regards,
Santosh
--
View this message in context: http://hdf-forum.184993.n3.nabble.com/Write-Variable-length-record-to-HDF5-file-tp1678291p1678291.html
Sent from the hdf-forum mailing list archive at Nabble.com.
_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
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Elena Pourmal wrote:
Santosh,
Similar performance issue was reported on this list in the past
(see
http://hdf-forum.184993.n3.nabble.com/Variable-length-types-slowness-td195101.html#a195101)
The fix is scheduled for 1.8.7 (May 2011), but we will let everyone on
this list know when it becomes available in a snapshot (hopefully before
Thanksgiving if things go according to the plan
Thank you!
Elena
~~~~~~~~~~~~~~~~~~~~~
Elena Pourmal
The HDF Group
epourmal@hdfgroup.org
~~~~~~~~~~~~~~~~~~~~~
Hi,
I have fucntion in my code which writes variable length data to HDF5
file.
I have a dataset created as,
fileType = H5Tvlen_create(H5T_NATIVE_UCHAR)
'DataSpace' with Rank: 1 and Dims: 1;
And chunking enabled for the same.
A function writing a data to this dataset, is being called in loop.
Before writing to a dataset I extend the dimensions of the dataset as
well.
Till here, everything goes correct. i.e. I'm able to extend dataset with
this data type successfully.
But, when I call,
H5Dwrite (dset, memtype, memspace, filespace, H5P_DEFAULT,wdata);
CPU usage goes 100%.
Is it a normal behaviour that the H5DWrite API take such a huge part of
CPU
to write variable length of data?
-----
Best Regards,
Santosh
--
View this message in context:
http://hdf-forum.184993.n3.nabble.com/Write-Variable-length-record-to-HDF5-file-tp1678291p1678291.html
Sent from the hdf-forum mailing list archive at Nabble.com.
_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
Hello Elena,
First of all thank you very much for your kind reply. After studying various
advantages with HDF5 I had started implementing the same for my application.
Surprisingly, this problem has popped up and as this is a known problem with
HDF5, I think this is too late for me now to find out another approach
to make a solution to my problem.
Could you give me any alternate way to write variable length data in HDF5
file?
I tried using packet table, but the API for variable length data is not
available in 1.8.5, the one which I'm using... ;(
···
On Oct 11, 2010, at 12:04 AM, santoshdarekar wrote:
-----
Best Regards,
Santosh
--
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