[
https://issues.apache.org/jira/browse/PHOENIX-258?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15311539#comment-15311539
]
Lars Hofhansl commented on PHOENIX-258:
---------------------------------------
BTW... Here's the HBase logic in FilterList to AND filters together:
{code}
...
if (filter.filterAllRemaining()) {
return ReturnCode.NEXT_ROW;
}
ReturnCode code = filter.filterKeyValue(v);
switch (code) {
// Override INCLUDE and continue to evaluate.
case INCLUDE_AND_NEXT_COL:
rc = ReturnCode.INCLUDE_AND_NEXT_COL;
case INCLUDE:
transformed = filter.transformCell(transformed);
continue;
case SEEK_NEXT_USING_HINT:
seekHintFilter = filter;
return code;
default:
return code;
}
...
return rc;
{code}
So this will combine the filters correctly as long as they are ordered
correctly. For example a SKIP will cause the FilterList to SKIP, only if
earlier filters INCLUDE* can a later filter cause a SEEK.
Unless I hear objections I am going to commit this to 4.x tonight or tomorrow.
> Use skip scan when SELECT DISTINCT on leading row key column(s)
> ---------------------------------------------------------------
>
> Key: PHOENIX-258
> URL: https://issues.apache.org/jira/browse/PHOENIX-258
> Project: Phoenix
> Issue Type: Task
> Reporter: ryang-sfdc
> Assignee: Lars Hofhansl
> Fix For: 4.8.0
>
> Attachments: 258-WIP.txt, 258-v1.txt, 258-v10.txt, 258-v11.txt,
> 258-v12.txt, 258-v13.txt, 258-v14.txt, 258-v15.txt, 258-v16.txt, 258-v2.txt,
> 258-v3.txt, 258-v4.txt, 258-v5.txt, 258-v6.txt, 258-v7.txt, 258-v8.txt,
> 258-v9.txt, 258.txt, DistinctFixedPrefixFilter.java, in-clause.png
>
>
> create table(a varchar(32) not null, date date not null constraint pk primary
> key(a,date))
> [["PLAN"],["CLIENT PARALLEL 94-WAY FULL SCAN OVER foo"],[" SERVER
> AGGREGATE INTO ORDERED DISTINCT ROWS BY [a]"],["CLIENT MERGE SORT"]]
>
> We should skip scan.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
