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https://issues.apache.org/jira/browse/HBASE-7337?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13564032#comment-13564032
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Anoop Sam John commented on HBASE-7337:
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[~zhou wen jian]
When you scan data and your table having multiple versions for a cell, which
all versions the scan should return to be specified in Scan object. By default
HBase will return only the latest version. But you have setters on Scan object
using which you can tell to get more version.
SCVF is used to specify a column value check. If the condition is not satisfied
for a row, then that row will be fully filtered out from the returned results.
Here using latestVersionOnly = true , you are specifying to check the condition
only on the latest version. [*Not* that to return the latestVersion only in
result]If this is set as false, all the versions will be checked for the
condition and if any of the version value is satisfying the condition, that row
will get included. But remember SCVF can not specify to return only latest
version of cell or not. This is just for specifying the condition and all the
filter will see all the versions of cells. Which version to be returned is
decided down the line in another part of code which will be executed after this
Filter#filterKeyValue(KeyValue)
"SingleColumnValueFilter seems to get unavailble data" - Your heading says
getting unavailable data. Can you tell more? Or your problem is getting the
older versions?
As per your reply we can check whether some real bug is there or not. If no
issues we can close this.
> SingleColumnValueFilter seems to get unavailble data
> ----------------------------------------------------
>
> Key: HBASE-7337
> URL: https://issues.apache.org/jira/browse/HBASE-7337
> Project: HBase
> Issue Type: Bug
> Components: Filters
> Affects Versions: 0.94.3, 0.96.0
> Environment: 0.94
> Reporter: Zhou wenjian
> Assignee: Zhou wenjian
> Fix For: 0.96.0, 0.94.6
>
>
> put multi versions of a row.
> r1 cf:q version:1 value:1
> r1 cf:q version:2 value:3
> r1 cf:q version:3 value:2
> the filter in scan is set as below:
> SingleColumnValueFilter valueF = new SingleColumnValueFilter(
> family,qualifier,CompareOp.EQUAL,new BinaryComparator(Bytes
> .toBytes("2")));
> then i found all of the three versions will be emmitted, then i set
> latestVersionOnly to false, the result does no change.
> {code}
> public ReturnCode filterKeyValue(KeyValue keyValue) {
> // System.out.println("REMOVE KEY=" + keyValue.toString() + ", value=" +
> Bytes.toString(keyValue.getValue()));
> if (this.matchedColumn) {
> // We already found and matched the single column, all keys now pass
> return ReturnCode.INCLUDE;
> } else if (this.latestVersionOnly && this.foundColumn) {
> // We found but did not match the single column, skip to next row
> return ReturnCode.NEXT_ROW;
> }
> if (!keyValue.matchingColumn(this.columnFamily, this.columnQualifier)) {
> return ReturnCode.INCLUDE;
> }
> foundColumn = true;
> if (filterColumnValue(keyValue.getBuffer(),
> keyValue.getValueOffset(), keyValue.getValueLength())) {
> return this.latestVersionOnly? ReturnCode.NEXT_ROW: ReturnCode.INCLUDE;
> }
> this.matchedColumn = true;
> return ReturnCode.INCLUDE;
> }
> {code}
> From the code above, it seeems that version 3 will be first emmited, and set
> matchedColumn to true, which leads the following version 2 and 1 emmited too.
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