Tuesday, November 26, 2013

HBase : Filters

All filters are implemented on the server side.
This is called predicate push down.

You can define a new instance of the filter by using

a)Comparison Filters

Row Filter:
Gives the ability to filter data based on rowkeys.

Family Filter:
Used to filter column Families. Data is retrieved in a column family level.

Qualifier Filter:
Used to filter out specific column qualifier.

Value Filter:
Used to filter out columns with a specific value.

Dependent Column Filter:
It uses timestamp as the reference column and includes all other columns. It lets you specify a dependent column.

b)Dedicated Filters

This filter is used when you have exactly one column that decides if an entire row should be returned or not.

SingleColumnValueExclude Filter:
This is an exclude filter. You will not get the column as a part of your result.

Prefix Filter:
All rows that match this prefix are returned the client.

Page Filter:
You specify the pagesize for your filter. This controls how many rows per page should be returned.

More Later..