- #Data analysis programs hive deduce how to#
- #Data analysis programs hive deduce code#
if no column-name is given, then the Hive column will map to all columns in the corresponding HBase column family, and the Hive MAP datatype must be used to allow access to these (possibly sparse) columns. (note that before HIVE-1228 in Hive 0.6, :key was not supported, and the first Hive column implicitly mapped to the key as of Hive 0.6, it is now strongly recommended that you always specify the key explictly we will drop support for implicit key mapping in the future). there must be exactly one :key mapping (this can be mapped either to a string or struct column–see Simple Composite Keys and Complex Composite Keys). If you specify a column as binary the bytes in the corresponding HBase cells are expected to be of the form that HBase's Bytes class yields. Any prefixes of the valid values are valid too (i.e. If no type specification is given the value from .type will be used. a mapping entry must be either :key, :timestamp or of the form column-family-name:[#(binary|string) (the type specification that delimited by # was added in Hive 0.9.0, earlier versions interpreted everything as strings). for each Hive column, the table creator must specify a corresponding entry in the comma-delimited string (so for a Hive table with n columns, the string should have n entries) whitespace should not be used in between entries since these will be interperted as part of the column name, which is almost certainly not what you want. 
The column mapping support currently available is somewhat cumbersome and restrictive:
.type: Can have a value of either string (the default) or binary, this option is only available as of Hive 0.9 and the string behavior is the only one available in earlier versions. There are two SERDEPROPERTIES that control the mapping of HBase columns to Hive: TBLPROPERTIES("" = "some_existing_table", "" = "some_existing_table") Īgain, is required (and will be validated against the existing HBase table's column families), whereas is optional. (Note that the jar locations and names have changed in Hive 0.9.0, so for earlier releases, some changes are needed.)ĬREATE EXTERNAL TABLE hbase_table_2(key int, value string) Here's an example using CLI from a source build environment, targeting a single-node HBase server. #Data analysis programs hive deduce how to#
See the HBase documentation for how to set up an HBase cluster. It also requires the correct configuration property to be set in order to connect to the right HBase master. The storage handler is built as an independent module, hive-hbase-handler-x.y.z.jar, which must be available on the Hive client auxpath, along with HBase, Guava and ZooKeeper jars. Storage Handlersīefore proceeding, please read StorageHandlers for an overview of the generic storage handler framework on which HBase integration depends. This feature is a work in progress, and suggestions for its improvement are very welcome. It is even possible to combine access to HBase tables with native Hive tables via joins and unions.Ī presentation is available from the HBase HUG10 Meetup This feature allows Hive QL statements to access HBase tables for both read (SELECT) and write (INSERT). This page documents the Hive/HBase integration support originally introduced in HIVE-705.
#Data analysis programs hive deduce code#
) Consumers wanting to work with HBase 1.x using Hive 1.x will need to compile Hive 1.x stream code themselves. Hive 2.x will be compatible with HBase 1.x and higher.
Hive 1.x will remain compatible with HBase 0.98.x and lower versions.
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