How to use TIMERANGE and VERSION in HBASE
In this issue, the editor will bring you about how to use TIMERANGE and VERSION in HBASE. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.
In HBase table creation, one version is specified by default (the default VERSION is 1 when creating the table). To retain multiple version information, you need to specify the number of versions when creating the table.
Eg.create 'scores', {NAME= >' course',VERSIONS= > 2}
First, create a table, and then add two records
Hbase (main): 079 scores', 0 > create 'scores', {NAME= >' course',VERSIONS= > 2}
0 row (s) in 0.9590 seconds
Hbase (main): 080 put 0 > scores','Tom','course:math','97'
0 row (s) in 0.0100 seconds
Hbase (main): 081 scan 0 > scores'
ROW COLUMN+CELL
Tom column=course:math, timestamp=1394097631387, value=97
1 row (s) in 0.0190 seconds
Hbase (main): 082 put 0 > scores','Tom','course:math','100'
0 row (s) in 0.0080 seconds
Hbase (main): 026 scan 0 > scores'
ROW COLUMN+CELL
Tom column=course:math, timestamp=1394097651029, value=100
1 row (s) in 0.0110 seconds
Hbase (main): 027scores', 0 > scan 'scores', {TIMERANGE= > [139409763138713 94097651029]}
ROW COLUMN+CELL
Tom column=course:math, timestamp=1394097631387, value=97
1 row (s) in 0.0210 seconds
Hbase (main): 028 scores', 0 > scan 'scores', {TIMERANGE= > [139409763138713 94097651030]}
ROW COLUMN+CELL
Tom column=course:math, timestamp=1394097651029, value=100
1 row (s) in 0.0100 seconds
As you can see from the above, the default result of HBASE scan is the record of the last timestamp, so how to scan both of them?
At this point, you can add VERSIONS as a constraint:
Hbase (main): 032scores', 0 > scan 'scores', {VERSIONS= > 2}
ROW COLUMN+CELL
Tom column=course:math, timestamp=1394097651029, value=100
Tom column=course:math, timestamp=1394097631387, value=97
1 row (s) in 0.0130 seconds
The above order has already scan out all this record.
Take a look at the following example:
Scan 'scores', {TIMERANGE= > [1394097631386, 1394097651029], VERSIONS= > 2}
ROW COLUMN+CELL
Tom column=course:math, timestamp=1394097631387, value=97
1 row (s) in 0.0130 seconds
There is only one scan record from the above results. You know, TIMERANGE means "> = start time and"
