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https://issues.apache.org/jira/browse/PHOENIX-2702?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15156241#comment-15156241
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Lars Hofhansl commented on PHOENIX-2702:
----------------------------------------
Sample output:
{noformat}
0: jdbc:phoenix:localhost> explain select count(*) from test where pk > 1300000;
+---------------------------------------------------------------------------------------------------+
| PLAN
|
+---------------------------------------------------------------------------------------------------+
| CLIENT 61-CHUNK ROWS 7069060 BYTES 629146340 PARALLEL 1-WAY RANGE SCAN OVER
TEST [1300001] - [*] |
| SERVER FILTER BY FIRST KEY ONLY
|
| SERVER AGGREGATE INTO SINGLE ROW
|
+---------------------------------------------------------------------------------------------------+
3 rows selected (0.01 seconds)
{noformat}
> Show estimate rows and bytes touched for explain plan.
> ------------------------------------------------------
>
> Key: PHOENIX-2702
> URL: https://issues.apache.org/jira/browse/PHOENIX-2702
> Project: Phoenix
> Issue Type: Bug
> Reporter: Lars Hofhansl
> Attachments: PHOENIX-2702.txt
>
>
> We can already estimate the size of a table (both rows and uncompressed
> bytes) with q query like this:
> {code}
> SELECT physical_name AS table_name, SUM(guide_posts_row_count) AS est_rows,
> SUM(guide_posts_width) AS est_size from SYSTEM.STATS GROUP BY physical_name;
> {code}
> During the planning phase we have more information, though. So we can report
> the actual numbers for a query during an explain since we have that info
> there anyway (we filtered the guidepost already with the key info provided in
> the query).
> I might whip up a quick patch for this.
> (Could also go further and add a est_count, est_size UDF for this, but that
> would be a bit harder to get hooked up at the right places, I think, and the
> meaning would be ambiguous)
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