Hive and HCatalog Integration
The HCatalog library provides applications with a table view of the file system layer in your cluster, expanding your application's options from read/write data streams to add table operations such as get row and store row. The HCatalog library stores the metadata required for its operations in the Hive Metastore.
The hcat
utility can execute any of the
data definition language (DDL) commands available in Hive that do
not involve launching a MapReduce application. Internally,
the hcat
utility passes DDL commands to
the hive
program. Data stored in the MapR
filesystem is serialized and deserialized
through InputStorageFormats
and OutputStorageFormats
objects
for records. Fields within a record are parsed
with SerDes
.
The
hive-json-serde-0.2.jar
JSON serializer/deserializer
has not implemented a serialize()
method and as a result does not
function.
The WebHCat server provides a REST-like web API for HCatalog. For more information about using WebHCat, see Hive and WebHCat Integration.
This section contains the following topics: