A Sunday 30 January 2011 23:38:48 Anthony Scopatz escrigué: > Hey Tom, > > On Sun, Jan 30, 2011 at 8:01 PM, Tom Fawcett <tom.fawc...@gmail.com> wrote: > > Thanks for your response. I suspect you are right that sets are > > not regular enough. Are all column types of fixed size? Is this > > a necessary condition for pytables? I though I’d seen an example > > of variable-length strings with pytables, but I maybe I was > > mistaken. > > Ahh Yes all columns are of a fixed size. What you probably saw with > strings is that you can store a length = 1, 2, .... N-1 string in a > length N string column. The string value simply determines where > (effectively) the null-terminated bytes goes. In terms of storage, > even a length zero string in a length N column will still take up > length N space in memory.
True, unless you use compression, in which case the storage requirements for variable length arrays can be reduced quite a lot (specially for large N, and when most of the strings are not as large). Cheers, -- Francesc Alted ------------------------------------------------------------------------------ Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! Finally, a world-class log management solution at an even better price-free! Download using promo code Free_Logger_4_Dev2Dev. Offer expires February 28th, so secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsight-sfd2d _______________________________________________ Pytables-users mailing list Pytables-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pytables-users
