[fitsbits] Fastest way to read a binary table

[William Pence]

Thierry Forveille wrote:
> 
> William Pence writes:
>  > In fact having too many buffers will hurt performance
>  > because CFITSIO then spends more time searching to see if the needed FITS
>  > block is already loaded in one of the buffers.  Recent tests on a 'typical'
>  > program seemed to show a slight improvement in overall I/O speed by
>  > increasing the number of buffers to a couple hundred, but increasing it to
>  > several thousand caused the program to run slower.
>  >
> Is that because CFITSIO performs an O(N) search through the buffer list? That
> would certainly make sense for N=50, but for a few thousand it probably
> becomes worth using hashing instead.

Yes, it is just does a simple sequential search through the buffer list.