On Fri, Mar 09, 2012 at 03:04:23PM -0500, Tom Lane wrote: > The main actual simplification would be in getting rid of the "hole" > at the end of each 4GB worth of WAL, cf this bit in xlog_internal.h: > > /* > * We break each logical log file (xlogid value) into segment files of the > * size indicated by XLOG_SEG_SIZE. One possible segment at the end of each > * log file is wasted, to ensure that we don't have problems representing > * last-byte-position-plus-1. > */ > #define XLogSegSize ((uint32) XLOG_SEG_SIZE) > #define XLogSegsPerFile (((uint32) 0xffffffff) / XLogSegSize) > #define XLogFileSize (XLogSegsPerFile * XLogSegSize) > > If we can't get rid of that and have a continuous 64-bit WAL address > space then it's unlikely we can actually simplify any logic. > > Now, doing that doesn't break the naming convention exactly; what it > changes is that there will be WAL files numbered xxxFFFF (for some > number of trailing-1-bits I'm too lazy to work out at the moment) where > before there were not. So the question really is how much external code > there is that is aware of that specific noncontiguous numbering behavior > and would be broken if things stopped being that way.
Our current WAL naming is hopelessly arcane, and we would certainly be benfitting users to simplify it. Is this a TODO? -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
