HColumnDescriptor and HTableDescriptor Support
This section describes the supported fields in the HColumnDescriptor and the HTableDescriptor classes.
HPE Ezmeral Data Fabric Database supports all of the methods that are in these classes. However, it supports only a subset of their fields.
HColumnDescriptor Class
Field | Description |
---|---|
BLOCKSIZE | Size of blocks in files stored to the filesytem (hfiles). |
BLOOMFILTER | Whether or not to use bloomfilters. |
COMPRESSION | Compression type. |
IN_MEMORY | Whether to serve from memory or not. |
MIN_VERSIONS | Minimum number of versions to keep. |
NAME | Name of the column family. |
TTL | Time to live of cell contents. |
VERSIONS | Number of versions to keep. |
HTableDescriptor Class
Field | Description |
---|---|
AUTOSPLIT |
Specifies whether to split the table into regions automatically as the
table grows. The average size of each region is determined by
the The default value is |
BULKLOAD | Boolean. Specifies whether to perform a full bulk load of the table. The
default is false . For more information, see Bulk Loading
and Data Fabric Tables. |
DELETE_TTL |
Used for multi-master replication. Normally, delete operations are purged after the affected table cells are updated. Whereas the result of an update is saved in a table until another change overwrites or deletes it, the result of a delete is not saved. In multi-master replication, this difference can lead to tables being unsynchronized. Example Suppose that you have set up multi-master replication between table
On
On
Now, though the put happened on
To ensure that both tables stay synchronized,
In general, the time-to-live for deletes should be greater than the amount of time that it takes replicated operations to reach replicas. By default, the value is 24 hours. For example, suppose (to extend the scenario above) that you pause
replication during weekdays and resume it on weekends. The put takes
place on Monday morning |
NAME | Name of the table. |