max_pt¶
This function is used to return the name of the largest level-1 partition that contains data in a partitioned table and read the data of this partition.
Syntax¶
max_pt(<table_full_name>)
Parameters¶
Parameter | Mandatory | Type | Description |
|---|---|---|---|
table_full_name | Yes | STRING | Specified table name. You must have the read permission on the table. |
Return Values¶
The return value is of the STRING type.
Note
The value of the largest level-1 partition is returned.
If a partition is added to a table using the ALTER TABLE command, but it does not contain any data, it will not be included in the returned values.
Example Code¶
For example, table1 is a partitioned table with partitions of 20120801 and 20120802, both of which contain data, and the max_pt value in the following statement will be 20120802. The DLI SQL statement will read data from the partition with pt = 20120802.
An example command is as follows:
select * from tablel where pt = max_pt('dbname.table1');
It is equivalent to the following statement:
select * from table1 where pt = (select max(pt) from dbname.table1);