# Collier interface¶

Internally, Recola makes use of Collier for the evaluation of tensor integrals. While most of the inteface is hidden from the user, the cache system can be tuned. In particular, we provide the following options:

• local cache mode: each process has its own cache, default
• global cache mode: a cache is setup to be shared among several processes

## Local mode¶

The local mode is fully automated and is used by default. For very challenging processes it is possible to reduce the memory consumption by splitting the cache for individual processes into several parts by calling:

 split_collier_cache_rcl set_collier_cache_rcl(npr, n)

## Global mode¶

The global cache mode needs to be activated explicitly and caches need to be switched manually using the following functions:

 set_cache_mode_rcl(mode) Sets the cache mode to mode. set_global_cache_rcl(ncache) Sets the number of active global caches to ncache. switch_global_cache_rcl(cache) Activates the cache with number cache.