restoreDB

Syntax

restoreDB(backupDir, dbPath, [newDBPath])

Arguments

backupDir is a string indicating the directory to save the backup.

dbPath is a string indicating the database path.

newDBPath is is a string indicating the new database name. The default value is dbPath.

Details

Restore the backup database. Return a table where each row is the restored database and table name.

Similar to function migrate, the function can restore a database, and the difference lies in:

migrate can restore all databases and tables under a directory, while restoreDB can only restore a database.
If the names of restored database and tables are the same as the originals, the original databases and tables must be deleted before calling migrate, which is not required by function restoreDB.

Note:

This function can only restore a database backed up by copying files (when dbPath is specified for function backup).
Make sure that the storage engine of the backed-up database is the same as the engine of newDBPath, and the partitionScheme (except for VALUE) must be the same. For a VALUE partitioned database, the partitioning scheme of the backup database must be a subset of that of the database to be restored.

Examples

$ dbName = "dfs://compoDB2"
$ n=1000
$ ID=rand("a"+string(1..10), n)
$ dates=2017.08.07..2017.08.11
$ date=rand(dates, n)
$ x=rand(10, n)
$ t=table(ID, date, x)
$ db1 = database(, VALUE, 2017.08.07..2017.08.11)
$ db2 = database(, HASH,[INT, 20])
$ if(existsDatabase(dbName)){
$      dropDatabase(dbName)
$ }
$ db = database(dbName, COMPO,[ db1,db2])

//create 2 tables
$ pt1 = db.createPartitionedTable(t, `pt1, `date`x).append!(t)
$ pt2 = db.createPartitionedTable(t, `pt2, `date`x).append!(t)

$ backupDB(backupDir, dbName)

$ restoreDB(backupDir, dbName)

dbName	tableName
dfs://compoDB2	pt1
dfs://compoDB2	pt2

Related functions: restore, restoreTable, migrate, backup, backupDB, backupTable