restoreTable
Syntax
restoreTable(backupDir, dbPath, tableName, [newDBPath],
[newTableName])
Arguments
backupDir is a string indicating the directory to save the backup.
dbPath is a string indicating the database path.
tableName is a string indicating the table name.
newDBPath (optional) is a string indicating the new database name. The default value is dbPath.
newTableName (optional) is a string indicating the new table name. The default value is tableName.
Details
Restore the backup database. Return a table where each row is the restored database
and table name. The function is equivalent to restore(backupDir, dbPath,
tableName, force=false, parallel=true, snapshot=true)
.
Similar to function migrate, the function can restore all tables of a database, and the difference lies in:
-
migrate
can restore all databases and tables under a directory, whilerestoreTable
can only restore a table. -
When the names of restored database and tables are the same as the originals, the original database and tables must be deleted before calling
migrate
, which is not required by functionrestoreTable
.
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)
restoreTable(backupDir,"dfs://compoDB2",`pt1)
dbName | tableName |
---|---|
dfs://compoDB2 | pt1 |
Related functions: restore, restoreDB, migrate, backup, backupDB, backupTable