diff options
Diffstat (limited to 'src/libstore/local-store.cc')
| -rw-r--r-- | src/libstore/local-store.cc | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc index 6f3d9efa8625..bddcbad12bcf 100644 --- a/src/libstore/local-store.cc +++ b/src/libstore/local-store.cc @@ -298,10 +298,20 @@ void LocalStore::openDB(bool create) if (sqlite3_exec(db, ("pragma synchronous = " + syncMode + ";").c_str(), 0, 0, 0) != SQLITE_OK) throw SQLiteError(db, "setting synchronous mode"); - /* Use `truncate' journal mode, which should be a bit faster. */ - if (sqlite3_exec(db, "pragma main.journal_mode = truncate;", 0, 0, 0) != SQLITE_OK) + /* Set the SQLite journal mode. The default is write-ahead + logging since it's the fastest and supports more concurrency. + The downside is that it doesn't work over NFS, so allow + truncate mode alternatively. */ + string mode = queryBoolSetting("use-sqlite-wal", true) ? "wal" : "truncate"; + if (sqlite3_exec(db, ("pragma main.journal_mode = " + mode + ";").c_str(), 0, 0, 0) != SQLITE_OK) throw SQLiteError(db, "setting journal mode"); + /* Increase the auto-checkpoint interval to 8192 pages. This + seems enough to ensure that instantiating the NixOS system + derivation is done in a single fsync(). */ + if (sqlite3_exec(db, "pragma wal_autocheckpoint = 8192;", 0, 0, 0) != SQLITE_OK) + throw SQLiteError(db, "setting autocheckpoint interval"); + /* Initialise the database schema, if necessary. */ if (create) { #include "schema.sql.hh" |