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changes.mady.by.user Ian Cook

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changes.mady.by.user Eugene Koifman

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EXPORT and IMPORT commands are also available (as of Hive 0.8).

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  • Vectorization will be turned off for delete operations.  This is automatic and requires no action on the part of the user.  Non-delete operations are not affected.  Tables with deleted data can still be queried using vectorization.
  • In version 0.14 it is recommended that you set hive.optimize.sort.dynamic.partition=false when doing deletes, as this produces more efficient execution plans.

 

Merge

Note
titleVersion Information

MERGE is available starting in Hive 2.2.

Merge can only be performed on tables that support ACID. See Hive Transactions for details.

Syntax
Code Block
Standard Syntax:
MERGE INTO <target table> AS T USING <source expression/table> AS S
ON <boolean expression>
WHEN MATCHED [AND <boolean expression>] THEN UPDATE SET <set clause list>
WHEN MATCHED [AND <boolean expression>] THEN DELETE
WHEN NOT MATCHED [AND <boolean expression>] THEN INSERT VALUES<value list>
Synopsis
  • In Hive 2.2, upon successful completion of this operation the changes will be auto-committed.
Notes
  • 1,2 or 3 WHEN clauses may be present; at most 1 of each type: UPDATE/DELETE/INSERT
  • WHEN NOT MATCHED must be the last WHEN clause
  • If both UPDATE and DELETE clauses are present, the 1st one in the statement must include [AND <boolean expression>]
  • Vectorization will be turned off for merge operations.  This is automatic and requires no action on the part of the user.  Non-delete operations are not affected.  Tables with deleted data can still be queried using vectorization.