From 5ce52f3dd831c623b8899dc4d5655c2d958fa6a0 Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Sun, 10 May 2020 22:37:13 +0000 Subject: overidx: document the SQLite PRAGMA we use This ought to prevent cargo-culting the cache_size PRAGMA into smaller SQLite DBs we might use. --- lib/PublicInbox/OverIdx.pm | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'lib') diff --git a/lib/PublicInbox/OverIdx.pm b/lib/PublicInbox/OverIdx.pm index acbf2c8d..cb15baad 100644 --- a/lib/PublicInbox/OverIdx.pm +++ b/lib/PublicInbox/OverIdx.pm @@ -21,8 +21,16 @@ use PublicInbox::Search; sub dbh_new { my ($self) = @_; my $dbh = $self->SUPER::dbh_new(1); + + # TRUNCATE reduces I/O compared to the default (DELETE) $dbh->do('PRAGMA journal_mode = TRUNCATE'); + + # 80000 pages (80MiB on SQLite <3.12.0, 320MiB on 3.12.0+) + # was found to be good in 2018 during the large LKML import + # at the time. This ought to be configurable based on HW + # and inbox size; I suspect it's overkill for many inboxes. $dbh->do('PRAGMA cache_size = 80000'); + create_tables($dbh); $dbh; } -- cgit v1.2.3-24-ge0c7