I guess this may have a place if your application data is transient in nature and doesn’t need to be retained forever.<\/p>\n
We first take an existing table and for a given column family set its “time to live” to 30 seconds. According to the documentation, the cell will be removed after this time.<\/p>\n
\r\nhbase(main):010:0> disable 'myxml'\r\n0 row(s) in 2.0870 seconds\r\n\r\nhbase(main):011:0> alter 'myxml', {NAME => 'xmlfamily', TTL => '30'}\r\n0 row(s) in 0.1080 seconds\r\n\r\nhbase(main):012:0> enable 'myxml'\r\n0 row(s) in 2.0770 seconds\r\n<\/pre>\nWe then insert a row…<\/p>\n
\r\nhbase(main):013:0> put 'myxml', '1', 'xmlfamily:mdata_xml', 'foo<\/x>'\r\n0 row(s) in 1.0980 seconds\r\n<\/pre>\n…and show that it exists right now…<\/p>\n
\r\nhbase(main):014:0> scan 'myxml'\r\nROW COLUMN+CELL\r\n 1 column=xmlfamily:mdata_xml, timestamp=1310152994856, value=foo<\/x>\r\n1 row(s) in 0.2890 seconds\r\n\r\nhbase(main):015:0> get 'myxml', '1'\r\nCOLUMN CELL\r\n xmlfamily:mdata_xml timestamp=1310152994856, value=foo<\/x>\r\n1 row(s) in 0.4170 seconds\r\n<\/pre>\n…but after we wait a minute or so, it is “gone”…<\/p>\n
\r\nhbase(main):016:0> get 'myxml', '1'\r\nCOLUMN CELL\r\n0 row(s) in 0.0490 seconds\r\n\r\nhbase(main):017:0>\r\n<\/pre>\nIt should be noted that the default TTL for a column family is 2,147,483,647 seconds, which is roughly 68 years. As such, we should be safe \ud83d\ude42<\/p>\n","protected":false},"excerpt":{"rendered":"
I guess this may have a place if your application data is transient in nature and doesn’t need to be retained forever. We first take an existing table and for a given column family set its “time to live” to…<\/p>\n