QED数据库使用笔记之Connection properties

Name	Default	Description
mode	from Config: qed.defaultMode	Read-only or read-write access to the database: rw: Read-write (the default) r: Read-only, intended for deployment on read-only media
isCaseSensitive	from Config: qed.isCaseSensitive	A boolean flag specifying whether string (VARCHAR) items are case-sensitive.
create	false	If "true", the database will be created if it doesn't already exist.
blockSize	from Config: qed.blockSize	The database block size, which must be a power of two. Maximum size: 32768, Minimum recommended size: 4096.
cacheSize	from Config: qed.cacheSize	The database cache size. A certain number of blocks are cached in an LRU cache; this parameter controls the size of this cache.
scratchCacheSize	from Config: qed.scratchCacheSize	The database scratch cache size, used for caching access to the database temporary (or "scratch") file. A certain number of blocks are cached in an LRU cache; this parameter controls the size of this cache.
useLockFile	true	A boolean. If true, a lock file will be used to protect from database corruption which might result from multiple processes accessing the same database simultaneously.
force	false	QED uses a lockfile to prevent multiple JVMs from accessing the database files simultaneously, which could lead to database corruption. When the JVM exits normally, this lockfile is deleted. If the JVM exits abnormally the lockfile may be left behind, and subsequent attempts to access the database will fail because of the old lockfile. If force is true, the database connection will succeed even if the lockfile is present. This option should be used with extreme care, since if there really is another process accessing the database, corruption may result.
logger	2	If no transaction logging is required (i.e., no rollback or recovery), then use '0'. Otherwise, use '2', (the default)
scratchDir	database directory	Specify the directory where scratch files are written. This option is most useful in conjunction with mode=r, where the database files can be located on read-only media, and the scratch directory can be located separately.
fastSync	true	If true, omit time-consuming sync operations to permit greater throughput.
minSyncInterval	from config:qed.minSyncInterval	Minimum interval between syncs. Set to zero to ensure a sync after every transaction.
maxSyncInterval	from config:qed.maxSyncInterval	Maximum interval between syncs. Use this to help limit the logfile, scratch, and before-images files.
minLogSize	128 K bytes	For loggers which support rollback, the minimum size at which a logging checkpoint operation will occur. The logging checkpoint cleans the log of entries which correspond to completed transactions.
qed.deletedRowCache	1000	Maximum number of deleted rows before we go to disk.
encrypt	false	On database creation (i.e., datafile doesn't yet exist and 'create=true'), if encrypt == true, then a low-level block encryption algorithm (the default is Rijndael) will be selected, seeded with the values of the user and passwd properties for this, connecting, user. The database magic code will be changed from 04 0c to 0e 0c to signal the encrypted content.