Make DROP DATABASE command generate less WAL records. Previously DROP DATABASE generated as many XLOG_DBASE_DROP WAL records as the number of tablespaces that the database to drop uses. This caused the scans of shared_buffers as many times as the number of the tablespaces during recovery because WAL replay of one XLOG_DBASE_DROP record needs that full scan. This could make the recovery time longer especially when shared_buffers is large.
This commit changes DROP DATABASE so that it generates only one XLOG_DBASE_DROP record, and registers the information of all the tablespaces into it. Then, WAL replay of XLOG_DBASE_DROP record needs full scan of shared_buffers only once, and which may improve the recovery performance. Author: Fujii Masao Reviewed-by: Kirk Jamison, Simon Riggs Discussion: https://postgr.es/m/cahgqgwf8ywnh0zal+2wjzpkj+ji9uhc+z4scng97wktvy5l...@mail.gmail.com Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/e6d8069522c8bde8239dd1fedfb4984efa4b3a1a Modified Files -------------- src/backend/access/rmgrdesc/dbasedesc.c | 7 +++- src/backend/commands/dbcommands.c | 67 +++++++++++++++++++++++---------- src/include/commands/dbcommands_xlog.h | 5 ++- 3 files changed, 56 insertions(+), 23 deletions(-)
