On 9/17/07, Tom Lane <[EMAIL PROTECTED]> wrote: > > Hmm ... so all that logic to prune just one tuple chain is dead code, > because heap_page_prune_defrag() ignores its pruneoff argument and > always passes InvalidOffsetNumber down to heap_page_prune(). > > While this is certainly a fairly trivial bug, it makes me wonder whether > the prune-one-chain logic has ever been active and whether there is any > real evidence for having it at all. Was this error introduced in some > recent refactoring, or has it always been like that?
This was introduced in the recent refactoring (the whole discussion of pruning/defragmentation started after that post) Earlier we used to prune single chain during index scans. In fact, I intentionally left the code that way because we are still debating the issue and I wanted to keep the infrastructure there even if there are no users of it right now. Given the way that > the logic works now, in particular that we always insist on doing > defrag, what point is there in not pruning all the chains when we can? > > Yeah, unless we separate pruning and defragmentation, there is no real value for single chain pruning. Defragmentation is a costly operation and we would want to prune as many chains before calling it. Thanks, Pavan -- Pavan Deolasee EnterpriseDB http://www.enterprisedb.com
