[Pytables-users] variable length strings in tables?

[Jeff R. <jr...@ya...>]

Hi,
 
Pandas uses pytables as a storage backend and has worked out quite well
fyi ... http://pandas.pydata.org/pandas-docs/dev/io.html#hdf5-pytables
 
I have a particular use case where I build a table, then later append to it.
Fixed types are no problem. However, I often index these tables by StringCols, which I pre-allocated
to the largest size I think that i'll need. So, wanted to think about supporting
variable-length string columns in the table.
 
any thoughts on these strategies:
1) any way to directly support a variable-length string in a particular column? (e.g. VLStringCol doesn't exist but a stand-alone VLStringAtom does)
2) As an alternative, I could store along with the table a VLArray the same # of rows as the table and keep string data here
   -- of course have to keep the synchronization up to date (and this doesn't help with an 'indexing' column, just with 'data' columns)
 
thanks,
 
Jeff