From f204274191f742deb489f53ebead03a0ed0a48eb Mon Sep 17 00:00:00 2001 From: Bruce Momjian Date: Sat, 16 Sep 2006 22:06:54 +0000 Subject: [PATCH] Update TODO for short header versions: < o Reorder physical storage order to reduce padding? < < This involves having the user-specified order of columns < be different from the physical order. SELECT * would < need to reorder the physical values to match the < user-specified ordering. < < o Store disk pages with no alignment/padding? < < This necessitates adding CPU-required padding when moving < rows from disk to memory. < < One idea is to store the header in network byte order (high bits < first), and read the high bits to determine the header length. < http://archives.postgresql.org/pgsql-hackers/2006-09/msg00848.php > One idea is to create zero-or-one-byte-header versions > of varlena data types. In involves setting the high-bit and > 0-127 length in the single-byte header, or clear the high bit > and store the 7-bit ASCII value in the rest of the byte. > The small-header versions have no alignment requirements. > http://archives.postgresql.org/pgsql-hackers/2006-09/msg01372.php --- doc/TODO | 23 +++++++---------------- doc/src/FAQ/TODO.html | 23 ++++++++--------------- 2 files changed, 15 insertions(+), 31 deletions(-) diff --git a/doc/TODO b/doc/TODO index bc3fdf66d9..e2d89492ee 100644 --- a/doc/TODO +++ b/doc/TODO @@ -2,7 +2,7 @@ PostgreSQL TODO List ==================== Current maintainer: Bruce Momjian (bruce@momjian.us) -Last updated: Thu Sep 14 17:43:58 EDT 2006 +Last updated: Sat Sep 16 18:06:27 EDT 2006 The most recent version of this document can be viewed at http://www.postgresql.org/docs/faqs.TODO.html. @@ -1353,23 +1353,14 @@ Miscellaneous Performance * Consider ways of storing rows more compactly on disk - o Reorder physical storage order to reduce padding? - - This involves having the user-specified order of columns - be different from the physical order. SELECT * would - need to reorder the physical values to match the - user-specified ordering. - - o Store disk pages with no alignment/padding? - - This necessitates adding CPU-required padding when moving - rows from disk to memory. - o Support a smaller header for short variable-length fields? - One idea is to store the header in network byte order (high bits - first), and read the high bits to determine the header length. - http://archives.postgresql.org/pgsql-hackers/2006-09/msg00848.php + One idea is to create zero-or-one-byte-header versions + of varlena data types. In involves setting the high-bit and + 0-127 length in the single-byte header, or clear the high bit + and store the 7-bit ASCII value in the rest of the byte. + The small-header versions have no alignment requirements. + http://archives.postgresql.org/pgsql-hackers/2006-09/msg01372.php o Reduce the row header size? diff --git a/doc/src/FAQ/TODO.html b/doc/src/FAQ/TODO.html index bd242da50d..ed40f3d6de 100644 --- a/doc/src/FAQ/TODO.html +++ b/doc/src/FAQ/TODO.html @@ -8,7 +8,7 @@

PostgreSQL TODO List

Current maintainer: Bruce Momjian (bruce@momjian.us)
-Last updated: Thu Sep 14 17:43:58 EDT 2006 +Last updated: Sat Sep 16 18:06:27 EDT 2006

The most recent version of this document can be viewed at
http://www.postgresql.org/docs/faqs.TODO.html. @@ -1219,20 +1219,13 @@ first.

  • Consider ways of storing rows more compactly on disk