On Mon, 2007-07-23 at 14:19 -0400, Tom Lane wrote: > "Simon Riggs" <[EMAIL PROTECTED]> writes: > > currPos and markPos are defined as BTScanPosData, which is an array of > > BTScanPosItems. That makes BTScanOpaqueData up to 8232 bytes, which > > seems wasteful since markPos is only ever used during merge joins. Most > > of that space isn't even used during merge joins either, we just do that > > to slightly optimise the speed of the restore during merge joins. > > Ah. I was seeing it as 6600 bytes on HPPA and 6608 on x86_64, but > I forgot that both of those architectures have MAXALIGN = 8. On a > MAXALIGN = 4 machine, MaxIndexTuplesPerPage will be significantly > larger, leading to larger BTScanPosData. > > Not sure it's worth fooling with, given that these days almost everyone > who's seriously concerned about performance is probably using 64bit > hardware. One less malloc cycle per indexscan is never going to be a > measurable savings anyway...
Oh sure, I was thinking to avoid Solaris' mutex by avoiding malloc() completely. -- Simon Riggs EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
