Can Hive tables be indexed?

Introduction to Indexes in Hive. Indexes are a pointer or reference to a record in a table as in relational databases. Indexing is a relatively new feature in Hive. In Hive, the index table is different than the main table.

How do I find the index in Hive?

Apache Hive Index Syntax is: CREATE INDEX index_name ON TABLE base_table_name (col_name.) AS ‘index.handler.class.name’ [WITH DEFERRED REBUILD] [IDXPROPERTIES (property_name=property_value.)]

What is Hive indexing?

The goal of Hive indexing is to improve the speed of query lookup on certain columns of a table. Without an index, queries with predicates like ‘WHERE tab1. col1 = 10’ load the entire table or partition and process all the rows.

What happens if an index is dropped in Hive?

An index can be dropped at any time with DROP INDEX. This will also cascade to the index table (if one exists). Attempting to drop an index table directly with DROP TABLE will fail. When an indexed base table is dropped, the DROP implicitly cascades to all indexes (and their corresponding index tables if any).

What do you mean by Index in hive?

Introduction to Indexes in Hive Indexes are a pointer or reference to a record in a table as in relational databases. Indexing is a relatively new feature in Hive. In Hive, the index table is different than the main table.

When to rebuild an index in hive educba?

This command ALTER INDEX….REBUILD is used to rebuild an index, which was already built on a table. Partition details should also be provided if the base table has partitions. Indexes need to be rebuilt if the underlying table is overwritten or appended.

Is the alter index name case sensitive in hive?

In Hive 0.12.0 and earlier releases, the index name is case-sensitive for CREATE INDEX and DROP INDEX statements. However, ALTER INDEX requires an index name that was created with lowercase letters (see HIVE-2752). This bug is fixed in Hive 0.13.0 by making index names case-insensitive for all HiveQL statements.

When was bitmap indexing added to Apache Hive?

But if an index exists for col1, then only a portion of the file needs to be loaded and processed. The improvement in query speed that an index can provide comes at the cost of additional processing to create the index and disk space to store the index. Hive indexing was added in version 0.7.0, and bitmap indexing was added in version 0.8.0.