Sage-Tips

How do I see Table properties in Hive?

Changing Hive table properties

1. Select the table you want to change and click View. The default Columns tab shows the table’s columns.
2. Click the Properties tab.
3. In the Table Parameters section, locate the skipAutoProvisioning property and (if it exists) verify that its value is set to “true”.

How do I get the last record in Hive?

You can use to_date function in your where clause to get only the max(Last uploaded date) records.

How do you validate a source and target table in Hive?

How to use the script

1. Create in Hive the “source-of-truth” database.
2. Create the source-of-truth “footable” table, taking care that the DDL is the same as the generated table (if the DDL is a bit different, there will be a problem with the validation.
3. Sqoop the table from the relational database.

How do I get the schema of a table in Hive?

In the Repository view, right-click the Hive connection of interest and select Retrieve schema from the contextual menu, and click Next on the wizard that opens to view and filter different tables in that Hive database.

How do I get metadata from Hive table?

When using Hive, you access metadata about schemas and tables by executing statements written in HiveQL (Hive’s version of SQL) such as SHOW TABLES . When using the HCatalog Connector, you can get metadata about the tables in the Hive database through several Vertica system tables.

How do I convert a string to a date in Hive?

2.3 to_date(string timestamp) – Converts Timestamp string to Date type. to_date() function takes timestamp as an input string in the default format yyyy-MM-dd HH:mm:ss and converts into Date type.

What is a hive Metastore?

What is Hive Metastore? Metastore is the central repository of Apache Hive metadata. It stores metadata for Hive tables (like their schema and location) and partitions in a relational database. It provides client access to this information by using metastore service API.

What happens when external table is dropped in hive?

When you drop a table from Hive Metastore, it removes the table/column data and their metadata. It can be a normal table (stored in Metastore) or an external table (stored in local file system); Hive treats both in the same manner, irrespective of their types.

What do you test for source file?

The Testing I have done is:

• Structure validation of the file.
• Check for duplicate records.
• Select one row from the target file and for that record alone, run the source query and then compare the Source output and the target record in the flat file manually comparing each field one at a time.
• Check for data truncation.

What is the data type of the to_date function in hive?

The timestamp format should in hive timestamp only. The return data type of to_date function varies from the version of the hive. Suppose the version is below 2.1.0 then its string. If the version is above 2.1.0, then the data type will be “date”.

How to get the value of transient_lastddltime in hive?

6 Get the transient_lastDdlTime from your Hive table. SHOW CREATE TABLE table_name; Then copy paste the transient_lastDdlTime in below query to get the value as timestamp. SELECT CAST(from_unixtime(your_transient_lastDdlTime_value) AS timestamp); Share Improve this answer Follow answered Dec 13 ’18 at 8:57 satznovasatznova

What are the timestamps supported by usehive?

Hive supports traditional UNIX timestamp data type with nanosecond upto 9 decimal precision (in Teradata it is till 6 decimal precision for timestamp data type). Typical TIMESTAMP data type has DATE part which is YEAR/MONTH/DAY and TIME part which is HOUR/MINUTE/SECOND/NanoSecond.

What is the use of Unix timestamp in Hadoop?

The UNIX timestamp function is helpful to get the timestamp information in the second format. It is generally useful to calculate the time difference with a different application in Hadoop like YARN, HBase, etc. The return data type of unix_timestamp function is “bigint”.