For complicated reasons I need to map an array of node IDs to a list of node bundles. That is, for a given list of node IDs, I need to get all the different bundles (node types) of the nodes the IDs belong to. The simple approach would be to load all the nodes, map that to their bundles and using array_unique to get the final list. Unfortunately, this is not a good solution because there may be hundreds of IDs in the array and loading all those nodes will result in a bad performance hit and/or go over the memory limit.
What is the best way to map an array of node IDs to (unique) node bundle types? Is there something built-in or does this require a custom database query? If so, I would be grateful for a dynamic query I could use for this (we're using MySQL). Thanks!