BRIN index and aborted transaction - Mailing list pgsql-hackers

Forgive me if this has been already discussed somewhere.

When a transaction aborts, it seems a BRIN index leaves summary data
which is not valid any more. Is this an expected behavior?  I guess
the answer is yes, because it does not affect correctness of a query
result, but I would like to make sure.

Second question is when the wrong summary data is gone? It seems
vacuum does not help. Do I have to recreate the index (or reindex)?

test=# begin;
BEGIN
test=# insert into t1 values(1000001);
INSERT 0 1
test=# SELECT * FROM brin_page_items(get_raw_page('brinidx', 2),'brinidx');itemoffset | blknum | attnum | allnulls |
hasnulls| placeholder |        value        
 
------------+--------+--------+----------+----------+-------------+---------------------         1 |      0 |      1 |
f       | f        | f           | {1 .. 28928}         2 |    128 |      1 | f        | f        | f           |
{28929.. 57856}         3 |    256 |      1 | f        | f        | f           | {57857 .. 86784}
 
[snip]        34 |   4224 |      1 | f        | f        | f           | {954625 .. 983552}        35 |   4352 |      1
|f        | f        | f           | {983553 .. 1000001}
 
(35 rows)

test=# abort;
ROLLBACK
test=# SELECT * FROM brin_page_items(get_raw_page('brinidx', 2),'brinidx');itemoffset | blknum | attnum | allnulls |
hasnulls| placeholder |        value        
 
------------+--------+--------+----------+----------+-------------+---------------------         1 |      0 |      1 |
f       | f        | f           | {1 .. 28928}         2 |    128 |      1 | f        | f        | f           |
{28929.. 57856}         3 |    256 |      1 | f        | f        | f           | {57857 .. 86784}
 
[snip]        34 |   4224 |      1 | f        | f        | f           | {954625 .. 983552}        35 |   4352 |      1
|f        | f        | f           | {983553 .. 1000001}
 
(35 rows)

test=# vacuum t1;
VACUUM
test=# SELECT * FROM brin_page_items(get_raw_page('brinidx', 2),'brinidx');itemoffset | blknum | attnum | allnulls |
hasnulls| placeholder |        value        
 
------------+--------+--------+----------+----------+-------------+---------------------         1 |      0 |      1 |
f       | f        | f           | {1 .. 28928}         2 |    128 |      1 | f        | f        | f           |
{28929.. 57856}         3 |    256 |      1 | f        | f        | f           | {57857 .. 86784}
 
[snip]        33 |   4096 |      1 | f        | f        | f           | {925697 .. 954624}        34 |   4224 |      1
|f        | f        | f           | {954625 .. 983552}        35 |   4352 |      1 | f        | f        | f
|{983553 .. 1000001}
 
(35 rows)

test=# select max(i) from t1;  max   
---------1000000
(1 row)
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp