On Fri, Feb 20, 2015 at 3:01 PM, Joaquin M Lopez Munoz wrote:

Olaf van der Spek writes:

...

Hi,

What's the memory consumption of ordered indices? Is it implemented as a linked list, so two pointers per element?

The overhead (on most platforms) is three pointers per node (and index):

http://stackoverflow.com/a/4208349/213114

Color is usually embedded into one of the pointers:

http://bannalia.blogspot.com/2008/11/optimizing-red-black-tree-color-bits.ht...

And for sequenced?

...

In that case for a write-only data structure an external ptr vector would make more sense wouldn't it?

What's a "write-only" structure supposed to be useful for? Anyway, s sorted vector is definitely better in terms of memory consumption than a single-index multi_index_container.

The data structure is filled once (data read from DB) and then queried lots. Perhaps a flat_map would be better suited. -- Olaf

Olaf van der Spek writes:

On Fri, Feb 20, 2015 at 3:01 PM, Joaquin M Lopez Munoz wrote:

...

The overhead (on most platforms) is three pointers per node (and index):

http://stackoverflow.com/a/4208349/213114

Color is usually embedded into one of the pointers:

http://bannalia.blogspot.com/2008/11/ optimizing-red-black-tree-color-bits.html

And for sequenced?

Two pointers per node.

[...]

...

What's a "write-only" structure supposed to be useful for? [...]

The data structure is filled once (data read from DB) and then queried lots.

I'd say "read only" is a more common name fo this usage pattern.

Perhaps a flat_map would be better suited.

If you only have one index, this is likely so --flat_map would give you the least memory overhead. Joaquín M López Muñoz Telefónica