MapR 5.1 is at End of Life (EOL) and no longer supported. Please see the latest documentation. This documentation is not being updated.

5.1 DB & Streams
This section covers the MapR-DB, MapR-Streams, and MapR-Gateways features. Each feature may contain both administrator and developer topics.
- MapR-DB
  - Architecture of MapR-DB
    MapR-DB's architecture gives it a large of advantages over other NoSQL databases.
  - Performance Enhancements for SSD Based MapR-DB Deployments
  - MapR-DB as a Document Database
    MapR-DB supports OJAI documents as a native data store. OJAI documents are stored in a compact binary format, not as plain ASCII text.
  - MapR-DB as a Wide-Column Database
    - Logical Model of MapR-DB Binary Tables
    - Filesystem Operations on MapR-DB Tables
    - Migrating Between Apache HBase Tables and MapR-DB Binary Tables
    - Designing Row Keys for MapR-DB Binary Tables
      A row key identifies a row in a MapR-DB binary table.
    - Designing Column Families for MapR-DB Binary Tables
      Scanning an entire table for matches can be very performance-intensive. Column families enable you to group related sets of data and restrict queries to a defined subset, leading to better performance. When you design a column family, think about what kinds of queries are going to be used the most often, and group your columns accordingly.
    - Configuring Maximum Row Sizes for Binary Tables
      The default maximum row size at installation is 32MB. You can configure this maximum by changing the value of the mfs.db.max.rowsize.kb parameter with the maprcli config save command.
    - Enabling Access to MapR Tables via HBase APIs, hbase shell, and MapReduce Jobs
    - Creating MapR-DB Binary Tables
    - Displaying Table Region Information for MapR-DB Tables
    - Creating Applications That Access MapR-DB Binary Tables
    - Bulk Loading and MapR-DB Binary Tables
      - Creating a MapR-DB Binary Table with Support for a Full Bulk Load
      - Writing Custom MapReduce Jobs for MapR-DB Using Bulk Loads
    - Replicating MapR-DB Binary Tables
    - Indexing MapR-DB Binary Tables with Elasticsearch
    - Impersonation via the HBase REST Gateway
- MapR Streams
  MapR Streams brings integrated publish/subscribe messaging to the MapR Converged Data Platform.
- MapR Gateways
  A MapR gateway mediates one-way communication between a source MapR cluster and a destination cluster. MapR-DB binary tables and MapR Streams streams can be replicated.

Creating a MapR-DB Binary Table with Support for a Full Bulk Load

When you create a MapR-DB binary table that you want to perform a full bulk load on, you must specify that you want to perform a full bulk load. Attempting a full bulk load on a table that does not have the bulk load attribute set to true results in an incremental bulk load being performed instead.

Using the maprcli table create command: Specify the value of the -bulkload parameter as true.
Using the hbase shell: Specify the value of the BULKLOAD parameter as true, as in the following example:

create '/a0','f1', BULKLOAD => 'true'

NOTE: If you want to pre-split a table, separate the BULKLOAD parameter from the SPLITS parameter, as in this example:

 hbase> create '/t1', 'f1', {SPLITS => ['10', '20', '30']}, {BULKLOAD => 'true'}

Using the MapR Control System (MCS): Select the Bulkload check box under Table Properties.

After completing a full bulk load, make the table available to client applications with one of the following commands. You do not have to use either of these commands if you used the CopyTable utility, which makes tables available to client applications automatically after a load is completed.

# maprcli table edit -path /user/juser/mytable -bulkload false (command line)

hbase shell> alter '/user/juser/mytable', 'f2', BULKLOAD => 'false' (hbase shell)

After you perform a full bulk load on a table, you cannot perform a full bulk load on it again. You cannot use the maprcli table edit command or hbase shell alter command to set the value to true again. In MCS, although the Bulkload check box is enabled after a table is created, selecting that check box and clicking OK in the Table Properties dialog generates an error message.