On Fri, 9 Aug 2024 at 18:10, Andreas Karlsson <andr...@proxel.se> wrote:
> On 8/8/24 2:18 PM, Abdoulaye Ba wrote: > > I am submitting a patch to add hooks for the functions > > pg_total_relation_size and pg_indexes_size. These hooks allow for custom > > behaviour to be injected into these functions, which can be useful for > > extensions and other custom PostgreSQL modifications. > > What kind of extensions do you imagine would use this hook? If it is for > custom index AMs I think adding this to the index AM interface would > make more sense than just adding a generic callback hook. > > Andreas > > The primary use case for this hook is to allow extensions to account for > additional storage mechanisms that are not covered by the default > PostgreSQL relation size calculations. For instance, in our project, we are > working with an external indexing system (Tantivy) that maintains > additional data structures outside the standard PostgreSQL storage. This > hook allows us to include the size of these additional structures in the > total relation size calculations. > > While I understand your suggestion about custom index AMs, the intent > behind this hook is broader. It is not limited to custom index types but > can also be used for other forms of external storage that need to be > accounted for in relation size calculations. This is why a generic callback > hook was chosen over extending the index AM interface. > > However, if there is a consensus that such a hook would be better suited > within the index AM interface for cases involving custom index storage, I'm > open to discussing this further and exploring how it could be integrated > more tightly with the existing PostgreSQL AM framework. >
