truncate
Syntax
truncate(dbUrl, tableName)
Details
Remove all rows from a DFS table but keep its schema. Command
truncate is faster than the delete statement
and the dropPartition function.
It is suggested to call function dropTable if you want to delete the schema of the table.
Parameters
dbUrl is a string indicating the DFS path of a database.
tableName is a string indicating the table name.
Returns
None.
Example
n=1000000
ID=rand(150, n)
dates=2017.08.07..2017.08.11
date=rand(dates, n)
x=rand(10.0, n)
t=table(ID, date, x)
dbDate = database(, VALUE, 2017.08.07..2017.08.11)
dbID = database(, RANGE, 0 50 100 150)
dbName="dfs://compoDB"
if(existsDatabase(dbName)){
dropDatabase(dbName)
}
db = database(dbName, COMPO, [dbDate, dbID])
pt = db.createPartitionedTable(t, `pt, `date`ID)
pt.append!(t);
truncate(dbName, `pt)
