【GaussDB】排查创建索引后查询数据行数发生变化的问题
背景
客户开发反馈，有个复杂的SQL，本来查询行数有几千行，针对其中一个表创建索引后，这个SQL查询行数只有一百多行了,重复多次执行都可以复现。
确认版本
GaussDB 内核为 506.0.0SPC0100， 已打修复跳扫BUG的热补丁（【GaussDB】执行索引跳扫时如果遇到该索引正在执行autovacuum，可能会导致数据查询不到）。而且因为重复执行能复现，因此理论上与之前这个VACUUM同时发生的BUG无关。
个人分析--20260202
隔壁驻场的同事发现执行计划里有索引跳扫，于是在有索引的情况下，把索引跳扫关闭，数据查询结果正常了。
得到这个信息后，我就开始逐段简化SQL，比较索引跳扫开关前后的表现，最后简化成了这样
select count(1) from tb1 where c2 in ('6','7');
这个表有68个字段，其中9个字段作为一个复合索引。
这个SQL走全表扫描出来的行数和走索引跳扫出来的行数不一致，索引跳扫的行数要小一些。但现在表里的数据量还有几十万行，不方便提交给华为，于是我继续缩小。
先减少行数：
drop table if exists tb2;
create table tb2 as select * from tb1 limit 10000;
create index ind_tb2 on tb2(c1,c2,c3,c4,c5,c6,c7,c8,c9);
select /*+IndexSkipScan(t ind_tb2)*/ count(1) from tb2 t where c2 in ('6','7');
select /*+fullscan(t)*/ count(1) from tb2 t where c2 in ('6','7');
反复测试，发现当limit 调整到188行时，仍能复现行数不一致，但limit 调整到187行时，两个行数就一致了。
再减少字段数，既然索引是9个字段，那么干脆就根据索引的这9个字段建一个9字段的表
create table t_test_skip as select c1, c2, c3, c4, c5, c6, c7, c8, c9 from tb1 limit 188;
CREATE INDEX ind_t_test_skip ON t_test_skip (c1, c2, c3, c4, c5, c6, c7, c8, c9) ;
select /*+IndexSkipScan(t ind_tb2)*/ count(1) from t_test_skip t where c2 in ('6','7');
select /*+tablescan(t)*/ count(1) from t_test_skip t where c2 in ('6','7');
果然还可以复现。
将这188行数据导出成insert sql，尝试注释中间的一些行，发现至少需要插入134行才能复现，全表扫比索引跳扫多2行。
最终复现的数据构造为
drop table if exists t_test_skip;
CREATE TABLE t_test_skip (
c1 character varying(1),
c2 character varying(1),
c3 character varying(8),
c4 character varying(3),
c5 numeric(19,3),
c6 numeric(19,3),
c7 character varying(2),
c8 numeric(19,3),
c9 character varying(10)
)
WITH (orientation=row, compression=no, storage_type=USTORE, segment=off);
CREATE INDEX ind_t_test_skip ON t_test_skip USING ubtree (c1, c2, c3, c4, c5, c6, c7, c8, c9) WITH (storage_type=USTORE) TABLESPACE pg_default;
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','1',NULL,'CNY',10000000.000,0.000,'5',0.000,'0022'),
('0','6','20080201','CNY',1000000.000,1000000.000,'2',1000000.000,'0028'),
('0','6','20080205','CNY',5000000.000,5000000.000,'3',5000000.000,'0028'),
('0','6','20080205','CNY',50000000.000,50000000.000,'2',50000000.000,'0047'),
('0','6','20080218','CNY',30000000.000,30000000.000,'1',30000000.000,'0028'),
('0','6','20080219','CNY',100000000.000,100000000.000,'2',100000000.000,'0047'),
('0','6','20080220','CNY',20000000.000,20000000.000,'1',20000000.000,'0028'),
('0','6','20080221','CNY',100000.000,100000.000,'2',100000.000,'0148'),
('0','6','20080221','CNY',100000.000,100000.000,'3',100000.000,'0148'),
('0','6','20080221','CNY',100000.000,100000.000,'4',100000.000,'0148');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080221','CNY',100000.000,100000.000,'5',100000.000,'0148'),
('0','6','20080222','CNY',10000000.000,10000000.000,'1',10000000.000,'0148'),
('0','6','20080222','CNY',15000000.000,15000000.000,'1',15000000.000,'0148'),
('0','6','20080222','CNY',20000000.000,20000000.000,'2',20000000.000,'0148'),
('0','6','20080225','CNY',26000000.000,26000000.000,'1',26000000.000,'0148'),
('0','6','20080225','CNY',30000000.000,30000000.000,'1',30000000.000,'0028'),
('0','6','20080225','CNY',70000000.000,70000000.000,'2',70000000.000,'0047'),
('0','6','20080228','CNY',30000000.000,30000000.000,'1',30000000.000,'0148'),
('0','6','20080229','CNY',5000000.000,5000000.000,'2',5000000.000,'0148'),
('0','6','20080229','CNY',10000000.000,10000000.000,'1',10000000.000,'0148');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080602','CNY',3000000.000,3000000.000,'5',3000000.000,'0049'),
('0','6','20080602','CNY',5000000.000,5000000.000,'2',5000000.000,'0018'),
('0','6','20080602','CNY',8000000.000,8000000.000,'3',8000000.000,'0049'),
('0','6','20080602','CNY',40000000.000,40000000.000,'1',40000000.000,'0005'),
('0','6','20080604','CNY',20000000.000,20000000.000,'1',20000000.000,'0125'),
('0','6','20080605','CNY',30000000.000,30000000.000,'1',30000000.000,'0005'),
('0','6','20080611','CNY',15000000.000,15000000.000,'3',15000000.000,'0096'),
('0','6','20080612','CNY',5000000.000,5000000.000,'1',5000000.000,'0151'),
('0','6','20080613','CNY',6000000.000,6000000.000,'1',6000000.000,'0151'),
('0','6','20080616','CNY',8000000.000,8000000.000,'2',8000000.000,'0073');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080617','CNY',6000000.000,6000000.000,'2',6000000.000,'0014'),
('0','6','20080617','CNY',6000000.000,6000000.000,'5',6000000.000,'0088'),
('0','6','20080617','CNY',16000000.000,16000000.000,'2',16000000.000,'0018'),
('0','6','20080618','CNY',5000000.000,5000000.000,'3',5000000.000,'0003'),
('0','6','20080618','CNY',29000000.000,29000000.000,'1',29000000.000,'0148'),
('0','6','20080618','CNY',40000000.000,40000000.000,'1',40000000.000,'0103'),
('0','6','20080618','CNY',75000000.000,75000000.000,'5',75000000.000,'0022'),
('0','6','20080618','CNY',110000000.000,110000000.000,'1',110000000.000,'0005'),
('0','6','20080619','CNY',5000.000,5000.000,'2',5000.000,'0336'),
('0','6','20080619','CNY',1189421.090,1189421.090,'2',1189421.090,'0025');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080619','CNY',2379174.080,2379174.080,'5',2379174.080,'0011'),
('0','6','20080619','CNY',6000000.000,6000000.000,'2',6000000.000,'0016'),
('0','6','20080619','CNY',29147311.650,29147311.650,'5',29147311.650,'0011'),
('0','6','20080619','CNY',29383832.150,29383832.150,'2',29383832.150,'0025'),
('0','6','20080619','CNY',76884993.630,76884993.630,'2',76884993.630,'0073'),
('0','6','20080707','CNY',5000000.000,5000000.000,'2',5000000.000,'0073'),
('0','6','20080707','CNY',10000000.000,10000000.000,'3',10000000.000,'0077'),
('0','6','20080708','CNY',150000.000,150000.000,'3',150000.000,'0156'),
('0','6','20080708','CNY',3000000.000,3000000.000,'5',3000000.000,'0011'),
('0','6','20080708','CNY',5000000.000,5000000.000,'2',5000000.000,'0014');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080708','CNY',6000000.000,6000000.000,'3',6000000.000,'0003'),
('0','6','20080709','CNY',10000000.000,10000000.000,'3',10000000.000,'0096'),
('0','6','20080710','CNY',10000.000,10000.000,'2',10000.000,'0121'),
('0','6','20080710','CNY',7000000.000,7000000.000,'1',7000000.000,'0270'),
('0','6','20080710','CNY',8000000.000,8000000.000,'1',8000000.000,'0234'),
('0','6','20080711','CNY',1000000.000,1000000.000,'1',1000000.000,'0345'),
('0','6','20080711','CNY',2000000.000,2000000.000,'1',2000000.000,'0003'),
('0','6','20080711','CNY',30000000.000,30000000.000,'2',30000000.000,'0047'),
('0','6','20080712','CNY',6000000.000,6000000.000,'1',6000000.000,'0234'),
('0','6','20080714','CNY',2000000.000,2000000.000,'5',2000000.000,'0022');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080714','CNY',5000000.000,5000000.000,'1',5000000.000,'0298'),
('0','6','20080714','CNY',5000000.000,5000000.000,'2',5000000.000,'0073'),
('0','6','20080714','CNY',5000000.000,5000000.000,'5',5000000.000,'0298'),
('0','6','20080714','CNY',8000000.000,8000000.000,'1',8000000.000,'0151'),
('0','6','20080714','CNY',10000000.000,10000000.000,'1',10000000.000,'0076'),
('0','6','20080714','CNY',10000000.000,10000000.000,'1',10000000.000,'0261'),
('0','6','20080714','CNY',10000000.000,10000000.000,'1',10000000.000,'0298'),
('0','6','20080714','CNY',10000000.000,10000000.000,'1',10000000.000,'0333'),
('0','6','20080714','CNY',10000000.000,10000000.000,'2',10000000.000,'0121'),
('0','6','20080714','CNY',10000000.000,10000000.000,'3',10000000.000,'0016');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080714','CNY',10000000.000,10000000.000,'3',10000000.000,'0042'),
('0','6','20080714','CNY',12000000.000,12000000.000,'1',12000000.000,'0136'),
('0','6','20080714','CNY',20000000.000,20000000.000,'1',20000000.000,'0358'),
('0','6','20080714','CNY',30000000.000,30000000.000,'2',30000000.000,'0008'),
('0','6','20080714','CNY',30000000.000,30000000.000,'3',30000000.000,'0148'),
('0','6','20080714','CNY',50000000.000,50000000.000,'1',50000000.000,'0103'),
('0','6','20080715','CNY',5000000.000,5000000.000,'1',5000000.000,'0086'),
('0','6','20080715','CNY',10000000.000,10000000.000,'2',10000000.000,'0088'),
('0','6','20080715','CNY',15000000.000,15000000.000,'3',15000000.000,'0052'),
('0','6','20080715','CNY',20000000.000,20000000.000,'3',20000000.000,'0134');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080716','CNY',1000000.000,1000000.000,'1',1000000.000,'0019'),
('0','6','20080716','CNY',2000000.000,2000000.000,'1',2000000.000,'0019'),
('0','6','20080716','CNY',2000000.000,2000000.000,'1',2000000.000,'0076'),
('0','6','20080716','CNY',4000000.000,4000000.000,'1',4000000.000,'0011'),
('0','6','20080716','CNY',5000000.000,5000000.000,'2',5000000.000,'0073'),
('0','6','20080716','CNY',9000000.000,9000000.000,'1',9000000.000,'0076'),
('0','6','20080716','CNY',20000000.000,20000000.000,'1',20000000.000,'0047'),
('0','6','20080716','CNY',30000000.000,30000000.000,'1',30000000.000,'0253'),
('0','6','20080716','CNY',35000000.000,35000000.000,'1',35000000.000,'0116'),
('0','6','20080717','CNY',10000000.000,10000000.000,'1',10000000.000,'0270');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080717','CNY',30000000.000,30000000.000,'2',30000000.000,'0121'),
('0','6','20080725','CNY',30000000.000,30000000.000,'2',30000000.000,'0028'),
('0','6','20080725','CNY',40000000.000,40000000.000,'2',40000000.000,'0047'),
('0','6','20080728','CNY',8000000.000,8000000.000,'3',8000000.000,'0042'),
('0','6','20080729','CNY',6000000.000,6000000.000,'2',6000000.000,'0325'),
('0','6','20080729','CNY',10000000.000,10000000.000,'1',10000000.000,'0136'),
('0','6','20080730','CNY',30000000.000,30000000.000,'3',30000000.000,'0077'),
('0','6','20080731','CNY',5000000.000,5000000.000,'5',5000000.000,'0028'),
('0','6','20080731','CNY',12000000.000,12000000.000,'1',12000000.000,'0234'),
('0','6','20080804','CNY',300000.000,300000.000,'3',300000.000,'0318');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080804','CNY',10000000.000,10000000.000,'3',10000000.000,'0134'),
('0','6','20080804','CNY',20000000.000,20000000.000,'1',20000000.000,'0007'),
('0','6','20080805','CNY',5000000.000,5000000.000,'2',5000000.000,'0277'),
('0','6','20080805','CNY',5000000.000,5000000.000,'5',5000000.000,'0022'),
('0','6','20080806','CNY',5000000.000,5000000.000,'5',5000000.000,'0067'),
('0','6','20080806','CNY',7000000.000,7000000.000,'2',7000000.000,'0298'),
('0','6','20080806','CNY',8000000.000,8000000.000,'1',8000000.000,'0003'),
('0','6','20080807','CNY',15000000.000,15000000.000,'5',15000000.000,'0298'),
('0','6','20080811','CNY',1000000.000,1000000.000,'1',1000000.000,'0013'),
('0','6','20080811','CNY',2000000.000,2000000.000,'3',2000000.000,'0013');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080811','CNY',10000000.000,10000000.000,'1',10000000.000,'0096'),
('0','6','20080811','CNY',20000000.000,20000000.000,'1',20000000.000,'0007'),
('0','6','20080811','CNY',35000000.000,35000000.000,'3',35000000.000,'0077'),
('0','6','20080812','CNY',1000000.000,1000000.000,'1',1000000.000,'0169'),
('0','6','20080812','CNY',3000000.000,3000000.000,'1',3000000.000,'0156'),
('0','6','20080812','CNY',8000000.000,8000000.000,'2',8000000.000,'0277'),
('0','6','20080812','CNY',10000000.000,10000000.000,'3',10000000.000,'0077'),
('0','6','20080812','CNY',20000000.000,20000000.000,'1',20000000.000,'0006'),
('0','6','20080812','CNY',20000000.000,20000000.000,'1',20000000.000,'0007'),
('0','6','20080812','CNY',20000000.000,20000000.000,'1',20000000.000,'0125');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('0','6','20080812','CNY',80000000.000,80000000.000,'5',80000000.000,'0047'),
('0','6','20080813','CNY',5000000.000,5000000.000,'5',5000000.000,'0011'),
('0','6','20080813','CNY',20000000.000,20000000.000,'3',20000000.000,'0042'),
('0','8','20080715','CNY',15000000.000,15000000.000,'3',0.000,'0052'),
('0','8','20080717','CNY',20000.000,20000.000,'1',0.000,'0076'),
('0','B',NULL,'CNY',1000.000,0.000,'2',0.000,'0248'),
('0','C',NULL,'CNY',6000000.000,6000000.000,'5',0.000,'0088');
INSERT INTO t_test_skip (c1,c2,c3,c4,c5,c6,c7,c8,c9) VALUES
('1','6','20080811','CNY',2.000,2.000,'1',2.000,'0183'),
('1','6','20080811','CNY',10000000.000,10000000.000,'1',10000000.000,'0037'),
('1','6','20080812','CNY',5000000.000,5000000.000,'3',5000000.000,'0016'),
('1','6','20080812','CNY',20000000.000,20000000.000,'1',20000000.000,'0037'),
('1','6','20080812','CNY',35000000.000,35000000.000,'3',35000000.000,'0077'),
('1','A',null,'CNY',15000000.000,0.000,'1',0.000,'0086'),
('1','B',null,'CNY',10000000.000,0.000,'2',0.000,'0016');
select /*+IndexSkipScan(t ind_t_test_skip)*/ count(1) from t_test_skip t where c2 in ('6','7'); --125 rows
select /*+tablescan(t)*/ count(1) from t_test_skip t where c2 in ('6','7'); --127 rows
gaussdb=# select /*+IndexSkipScan(t ind_t_test_skip)*/ count(1) from root.t_test_skip t where c2 in ('6','7');
count
-------
125
(1 row)
gaussdb=# select /*+tablescan(t)*/ count(1) from root.t_test_skip t where c2 in ('6','7');
count
-------
127
(1 row)
最后几行的数据似乎还是有些特别的
比如说c3最后两行有NULL，但尝试把这两个NULL改成有值，同样还是能复现问题；
然后C2是A/B ，也改成和上面一样的6 ，也还是能复现问题。
这意味着，可能与最后两行是什么值没有关系了，更可能与索引页面边界有关。
于是尝试比较插入133行的索引页面，和插入134行的索引页面，发现在133行时，索引页面有2个，但是插入第134行时，索引页面变成了4个。
目前没有GaussDB没有文档详细介绍rcr_ubtree的文件结构，只能先肉眼看看二进制文件能不能比出一些差异。
在134行表(左)和133行表（右）的索引文件里，最上面这个块（0h~2000h）长得差不多，只有一点点信息，然后下面全是空的
第2个块(2001h~3ff0h)就有些区别了，左边这个134行表的，多出了一些空的，但右边这个133行表的，空的就比较少，而且右边已经索引到了最后一行（可以发现 1.B.CNY），而134行的在第二个块里还不包含后面一部分数据
134行表索引的第三个块(4000h~5ff0h)比较空，有几行数据
134行表的索引第4个块里似乎有一行数据,但不完整，应该是无用的，没被vacuum掉
识别到 (0,6,20080813) 开始及后面的数据，在134行表的索引里，都在多出来的这第3个块里，跳扫少了的两行数据正好也在这个块里。
暂时不理解为什么已经有了第3个块，里面还有很多空的，为什么会有第4个块（难道是文档里说的双循环队列？）。但目前现象就是在索引跳扫的时候，刚好把第三个块里的前两个字段为 (0,6) 的数据给忽略掉了，第二个块前两个字段刚好也全是 (0,6)
考虑到跳扫其实是要自动拼接前导列的条件，因此怀疑此处是拼接的条件有误。
不过此处由于没有源码，暂时不好猜要怎么断点跟踪，有找到几个内核函数（find_scankey_with_old_value、update_skip_scankeys），也没法去观察了。
/usr1/GaussDBKernel/server/opengauss/src/compatibility/storage_adaptor/ipc/sinvaladt.cpp
/usr1/GaussDBKernel/server/opengauss/src/auxiliary/share/cache/inval.cpp
#1 0x000055fa4c976b42 in UBTreeSearch::update_skip_scankeys (this=0x7fb49fbba81f, scan=0x7fb4964e5050, indexRel=0x7fb496638f28) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/storage/index/ubtree/storage_ubtree_search.cpp:2131
#2 0x000055fa4c976bcb in UBTreeSearch::find_scankey_with_old_value (this=0x7fb49fbba81f, scan=0x7fb4964e5050, dir=FORWARD_SCAN_DIRECTION, scanstart=<optimized out>, offnum=@0x7fb49fbba6ce: 7) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/storage/index/ubtree/storage_ubtree_search.cpp:1767
#3 0x000055fa4c976d99 in UBTreeSearch::exec_skip_internal (this=0x7fb49fbba81f, scan=0x7fb4964e5050, dir=FORWARD_SCAN_DIRECTION, indexdir=FORWARD_SCAN_DIRECTION, scanstart=<optimized out>, prefix=1) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/storage/index/ubtree/storage_ubtree_search.cpp:2057
#4 0x000055fa4c977b90 in UBTreeSearch::exec_skip (this=0x7fb49fbba81f, scan=0x7fb4964e5050, dir=FORWARD_SCAN_DIRECTION, indexdir=FORWARD_SCAN_DIRECTION, scanstart=<optimized out>, prefix=1) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/storage/index/ubtree/storage_ubtree_search.cpp:1752
#5 0x000055fa4ca0076d in index_skip (scan=0x7fb4964e5050, direction=FORWARD_SCAN_DIRECTION, indexdir=<optimized out>, scanstart=<optimized out>, prefix=<optimized out>) at /usr1/GaussDBKernel/server/opengauss/src/compatibility/storage_adaptor/index/indexam.cpp:1328
#6 0x000055fa4b48988c in IndexOnlyScanOperator::get_next_internal (this=0x7fb498bd4050) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/executor/rowengine/executor_rowopr_indexonlyscan.cpp:197
#7 0x000055fa4b4e2d0d in gs_exec_scan_fetch<IndexOnlyScanOperator> (in_node=0x7fb498bd4050) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/executor/rowengine/framework/executor_framework_execscan.cpp:96
#8 0x000055fa4b4e2f22 in gs_exec_scan<IndexOnlyScanOperator> (in_node=0x7fb498bd4050) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/executor/rowengine/framework/executor_framework_execscan.cpp:131
#9 0x000055fa4b4d1d1a in PlanState::get_next (this=0x7fb498bd4050) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/executor/rowengine/framework/executor_framework_core.cpp:387
#10 0x000055fa4b46ddf9 in AggOperator::fetch_input_tuple (this=0x7fb40ef4c050) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/executor/rowengine/executor_rowopr_agg.cpp:132
#11 0x000055fa4b4731cd in AggOperator::agg_retrieve_direct (this=0x7fb40ef4c050) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/executor/rowengine/executor_rowopr_agg.cpp:1735
#12 0x000055fa4b473e55 in AggOperator::get_next (this=0x7fb40ef4c050) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/executor/rowengine/executor_rowopr_agg.cpp:1607
#13 0x000055fa4b4d1d1a in PlanState::get_next (this=0x7fb40ef4c050) at /usr1/GaussDBKernel/server/opengauss/src/gausskernel/executor/rowengine/framework/executor_framework_core.cpp:387
#14 0x000055fa4a695e46 in exec_execute_plan (bii_state=<optimized out>, dest=0x7fb48dc29f00, direction=<optimized out>, numberTuples=0, sendTuples=true, operation=CMD_SELECT, planstate=0x7fb40ef4c050, estate=0x7fb48dd60050) at /usr1/GaussDBKernel/server/opengauss/src/compatibility/sql_adaptor/utils/exec_main.cpp:2388
#15 exec_standard_executor_run (queryDesc=0x7fb48dc4d050, direction=<optimized out>, count=0) at /usr1/GaussDBKernel/server/opengauss/src/compatibility/sql_adaptor/utils/exec_main.cpp:899
#16 0x000055fa4ae6c11d in sqlcmd_explain_executor_run (query_desc=0x7fb48dc4d050, direction=FORWARD_SCAN_DIRECTION, count=0) at /usr1/GaussDBKernel/server/opengauss/src/compatibility/sql_adaptor/commands/auto_explain.cpp:113
#17 0x000055fa4a6963f2 in exec_executor_run (queryDesc=0x7fb48dc4d050, direction=FORWARD_SCAN_DIRECTION, count=0) at /usr1/GaussDBKernel/server/opengauss/src/compatibility/sql_adaptor/utils/exec_main.cpp:701
#18 0x000055fa4b36f5de in PortalRunSelect (portal=0x7fb48247e050, forward=true, count=0, dest=0x7fb48dc29f00) at /usr1/GaussDBKernel/server/opengauss/src/auxiliary/proc/tcop/pquery.cpp:1801
#19 0x000055fa4b370468 in PortalRun (portal=0x7fb48247e050, count=9223372036854775807, isTopLevel=true, dest=0x7fb48dc29f00, altdest=0x7fb48dc29f00, completionTag=0x7fb49fbbb260 "", snapshot=0x0, bii_state=0x0) at /usr1/GaussDBKernel/server/opengauss/src/auxiliary/proc/tcop/pquery.cpp:1469
#20 0x000055fa4b3d1490 in execute_with_cachedplan (cplan=<optimized out>, param_list_info=0x7fb498b96bc0, psrc=0x7fb496688850, parameterized_exec_inputs=0x7fb49fbbb220, saved_parse_tree=<optimized out>, es=0x0) at /usr1/GaussDBKernel/server/opengauss/src/compatibility/sql_adaptor/commands/parameterize/parameterized_core.cpp:143
#21 0x000055fa4b3d24f3 in execute_with_cachedplan (saved_parse_tree=<optimized out>, es=0x0, parameterized_exec_inputs=0x7fb49fbbb220, psrc=<optimized out>, param_list_info=<optimized out>, cplan=<optimized out>) at /usr1/GaussDBKernel/server/opengauss/src/compatibility/sql_adaptor/commands/parameterize/parameterized_core.cpp:528
#22 exec_parameterized_simple_query (raw_parse_tree=0x7fb49fbbb208, parameterized_exec_inputs=0x7fb49fbbb220) at /usr1/GaussDBKernel/server/opengauss/src/compatibility/sql_adaptor/commands/parameterize/parameterized_core.cpp:549
#23 0x000055fa4b356a78 in exec_simple_query (query_string=<optimized out>, msg=0x7fb49fbbb530, messageType=QUERY_MESSAGE) at /usr1/GaussDBKernel/server/opengauss/src/auxiliary/proc/tcop/postgres.cpp:3248
#24 0x000055fa4b362e38 in gs_process_command (firstchar=<optimized out>, input_message=0x7fb49fbbb530, send_ready_for_query=0x7fb49fbbb526) at /usr1/GaussDBKernel/server/opengauss/src/auxiliary/proc/tcop/postgres.cpp:11743
#25 0x000055fa4b3689c0 in PostgresMain (argc=<optimized out>, argv=0x7fb499565b20, dbname=<optimized out>, username=<optimized out>) at /usr1/GaussDBKernel/server/opengauss/src/auxiliary/proc/tcop/postgres.cpp:11313
#26 0x000055fa4b2ec2df in backend_run (port=0x7fb49fbbb890) at /usr1/GaussDBKernel/server/opengauss/src/auxiliary/proc/postmaster/postmaster.cpp:12482
#27 0x000055fa4b32b1b0 in gauss_db_worker_thread_main<(knl_thread_role)2> (arg=<optimized out>) at /usr1/GaussDBKernel/server/opengauss/src/auxiliary/proc/postmaster/postmaster.cpp:19086
#28 0x000055fa4b2ec39a in internal_thread_func (args=<optimized out>) at /usr1/GaussDBKernel/server/opengauss/src/auxiliary/proc/postmaster/postmaster.cpp:20196
#29 0x00007fb60f026f1b in ?? () from /usr/lib64/libpthread.so.0
#30 0x00007fb60ef5e320 in clone () from /usr/lib64/libc.so.6
后来华为oncall提供了一个函数可以解析索引文件
select * from gs_parse_page_bypath((select pg_relation_filepath('ind_t_test_skip')), -1, 'ubtree', true);
The target page is from disk.
UBtree index page information of block 0/3
pd_lsn: 13/5E007538 ,len 8 ,offset 0
pd_checksum: 0x2D87, verify success, len 2, offset 8
pd_flags: 0x40
pd_lower: 56, non-empty, len 2, offset 12
pd_upper: 8144, old page, len 2, offset 14
pd_special: 8144, size 48, len 2, offset 16
Page size & version: 8192, 5, len 2, offset 18
pd_prune_xid: 0
Meta Page Info: btm_level: 1, btm_fastlevel: 1, btm_root: 3, btm_fastroot: 3, btm_version: UBTREE_RCR_VERSION, btm_magic: 53162, btpo_flags: BTP_META, reltoastrelid: 0
UBTree index special information:
btree left sibling: 0
btree right sibling: 0
btree tree level: 0
btree flag: BTP_INTERNAL
btree cycle ID: 0
ubtree last_delete_xid: 0
ubtree xid_base: 0
ubtree active tuples: 0
The target page is from disk.
UBtree index page information of block 1/3
pd_lsn: 13/5E007538 ,len 8 ,offset 0
pd_checksum: 0x5592, verify success, len 2, offset 8
pd_flags: 0x40
pd_lower: 512, non-empty, len 2, offset 12
pd_upper: 1256, old page, len 2, offset 14
pd_special: 8144, size 48, len 2, offset 16
Page size & version: 8192, 5, len 2, offset 18
pd_prune_xid: 0
Index tuple information on this page
Tuple #1 is normal: length 24, offset 8120
Heap Tid: block 0/0, offset 3
ctid(0,3), tablebucketid -1, tableoid 0
Length: 24, has var-width attrs
Tuple #2 is normal: length 56, offset 8064
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 1
ctid(0,1), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs, has nulls
Tuple #3 is normal: length 56, offset 8008
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 2
ctid(0,2), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #4 is normal: length 56, offset 7952
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 3
ctid(0,3), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #5 is normal: length 56, offset 7896
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 4
ctid(0,4), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #6 is normal: length 56, offset 7840
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 5
ctid(0,5), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #7 is normal: length 56, offset 7784
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 6
ctid(0,6), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #8 is normal: length 56, offset 7728
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 7
ctid(0,7), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #9 is normal: length 56, offset 7672
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 8
ctid(0,8), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #10 is normal: length 56, offset 7616
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 9
ctid(0,9), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #11 is normal: length 56, offset 7560
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 10
ctid(0,10), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #12 is normal: length 56, offset 7504
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 11
ctid(0,11), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #13 is normal: length 56, offset 7448
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 12
ctid(0,12), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #14 is normal: length 56, offset 7392
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 13
ctid(0,13), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #15 is normal: length 56, offset 7336
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 14
ctid(0,14), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #16 is normal: length 56, offset 7280
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 15
ctid(0,15), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #17 is normal: length 56, offset 7224
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 16
ctid(0,16), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #18 is normal: length 56, offset 7168
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 17
ctid(0,17), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #19 is normal: length 56, offset 7112
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 18
ctid(0,18), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #20 is normal: length 56, offset 7056
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 19
ctid(0,19), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #21 is normal: length 56, offset 7000
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 20
ctid(0,20), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #22 is normal: length 56, offset 6944
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 21
ctid(0,21), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #23 is normal: length 56, offset 6888
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 22
ctid(0,22), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #24 is normal: length 56, offset 6832
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 23
ctid(0,23), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #25 is normal: length 56, offset 6776
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 24
ctid(0,24), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #26 is normal: length 56, offset 6720
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 25
ctid(0,25), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #27 is normal: length 56, offset 6664
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 26
ctid(0,26), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #28 is normal: length 56, offset 6608
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 27
ctid(0,27), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #29 is normal: length 56, offset 6552
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 28
ctid(0,28), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #30 is normal: length 56, offset 6496
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 29
ctid(0,29), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #31 is normal: length 56, offset 6440
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 30
ctid(0,30), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #32 is normal: length 56, offset 6384
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 31
ctid(0,31), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #33 is normal: length 56, offset 6328
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 32
ctid(0,32), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #34 is normal: length 56, offset 6272
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 33
ctid(0,33), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #35 is normal: length 56, offset 6216
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 34
ctid(0,34), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #36 is normal: length 56, offset 6160
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 35
ctid(0,35), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #37 is normal: length 56, offset 6104
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 36
ctid(0,36), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #38 is normal: length 56, offset 6048
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 37
ctid(0,37), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #39 is normal: length 64, offset 5984
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 38
ctid(0,38), tablebucketid -1, tableoid 0
Length: 56, has var-width attrs
Tuple #40 is normal: length 56, offset 5928
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 39
ctid(0,39), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #41 is normal: length 72, offset 5856
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 40
ctid(0,40), tablebucketid -1, tableoid 0
Length: 64, has var-width attrs
Tuple #42 is normal: length 72, offset 5784
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 41
ctid(0,41), tablebucketid -1, tableoid 0
Length: 64, has var-width attrs
Tuple #43 is normal: length 56, offset 5728
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 42
ctid(0,42), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #44 is normal: length 72, offset 5656
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 43
ctid(0,43), tablebucketid -1, tableoid 0
Length: 64, has var-width attrs
Tuple #45 is normal: length 72, offset 5584
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 44
ctid(0,44), tablebucketid -1, tableoid 0
Length: 64, has var-width attrs
Tuple #46 is normal: length 72, offset 5512
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 45
ctid(0,45), tablebucketid -1, tableoid 0
Length: 64, has var-width attrs
Tuple #47 is normal: length 56, offset 5456
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 46
ctid(0,46), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #48 is normal: length 56, offset 5400
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 47
ctid(0,47), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #49 is normal: length 56, offset 5344
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 48
ctid(0,48), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #50 is normal: length 56, offset 5288
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 49
ctid(0,49), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #51 is normal: length 56, offset 5232
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 50
ctid(0,50), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #52 is normal: length 56, offset 5176
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 51
ctid(0,51), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #53 is normal: length 56, offset 5120
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 52
ctid(0,52), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #54 is normal: length 56, offset 5064
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 53
ctid(0,53), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #55 is normal: length 56, offset 5008
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 54
ctid(0,54), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #56 is normal: length 56, offset 4952
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 55
ctid(0,55), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #57 is normal: length 56, offset 4896
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 56
ctid(0,56), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #58 is normal: length 56, offset 4840
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 57
ctid(0,57), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #59 is normal: length 56, offset 4784
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 58
ctid(0,58), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #60 is normal: length 56, offset 4728
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 59
ctid(0,59), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #61 is normal: length 56, offset 4672
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 60
ctid(0,60), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #62 is normal: length 56, offset 4616
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 61
ctid(0,61), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #63 is normal: length 56, offset 4560
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 62
ctid(0,62), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #64 is normal: length 56, offset 4504
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 63
ctid(0,63), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #65 is normal: length 56, offset 4448
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 64
ctid(0,64), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #66 is normal: length 56, offset 4392
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 65
ctid(0,65), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #67 is normal: length 56, offset 4336
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 66
ctid(0,66), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #68 is normal: length 56, offset 4280
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 67
ctid(0,67), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #69 is normal: length 56, offset 4224
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 68
ctid(0,68), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #70 is normal: length 56, offset 4168
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 69
ctid(0,69), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #71 is normal: length 56, offset 4112
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 70
ctid(0,70), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #72 is normal: length 56, offset 4056
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 71
ctid(0,71), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #73 is normal: length 56, offset 4000
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 72
ctid(0,72), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #74 is normal: length 56, offset 3944
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 73
ctid(0,73), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #75 is normal: length 56, offset 3888
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 74
ctid(0,74), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #76 is normal: length 56, offset 3832
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 75
ctid(0,75), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #77 is normal: length 56, offset 3776
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 76
ctid(0,76), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #78 is normal: length 56, offset 3720
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 77
ctid(0,77), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #79 is normal: length 56, offset 3664
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 78
ctid(0,78), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #80 is normal: length 56, offset 3608
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 79
ctid(0,79), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #81 is normal: length 56, offset 3552
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 80
ctid(0,80), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #82 is normal: length 56, offset 3496
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 81
ctid(0,81), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #83 is normal: length 56, offset 3440
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 82
ctid(0,82), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #84 is normal: length 56, offset 3384
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 83
ctid(0,83), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #85 is normal: length 56, offset 3328
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 84
ctid(0,84), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #86 is normal: length 56, offset 3272
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 85
ctid(0,85), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #87 is normal: length 56, offset 3216
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 86
ctid(0,86), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #88 is normal: length 56, offset 3160
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 87
ctid(0,87), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #89 is normal: length 56, offset 3104
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 88
ctid(0,88), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #90 is normal: length 56, offset 3048
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 89
ctid(0,89), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #91 is normal: length 56, offset 2992
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 90
ctid(0,90), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #92 is normal: length 56, offset 2936
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 91
ctid(0,91), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #93 is normal: length 56, offset 2880
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 92
ctid(0,92), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #94 is normal: length 56, offset 2824
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 93
ctid(0,93), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #95 is normal: length 56, offset 2768
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 94
ctid(0,94), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #96 is normal: length 56, offset 2712
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 95
ctid(0,95), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #97 is normal: length 56, offset 2656
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 96
ctid(0,96), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #98 is normal: length 56, offset 2600
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 97
ctid(0,97), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #99 is normal: length 56, offset 2544
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 98
ctid(0,98), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #100 is normal: length 56, offset 2488
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 99
ctid(0,99), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #101 is normal: length 56, offset 2432
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 100
ctid(0,100), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #102 is normal: length 56, offset 2376
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 101
ctid(0,101), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #103 is normal: length 56, offset 2320
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 102
ctid(0,102), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #104 is normal: length 56, offset 2264
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 103
ctid(0,103), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #105 is normal: length 56, offset 2208
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 104
ctid(0,104), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #106 is normal: length 56, offset 2152
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 105
ctid(0,105), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #107 is normal: length 56, offset 2096
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 106
ctid(0,106), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #108 is normal: length 56, offset 2040
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 107
ctid(0,107), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #109 is normal: length 56, offset 1984
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 108
ctid(0,108), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #110 is normal: length 56, offset 1928
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 109
ctid(0,109), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #111 is normal: length 56, offset 1872
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 110
ctid(0,110), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #112 is normal: length 56, offset 1816
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 111
ctid(0,111), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #113 is normal: length 56, offset 1760
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 112
ctid(0,112), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #114 is normal: length 56, offset 1704
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 113
ctid(0,113), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #115 is normal: length 56, offset 1648
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 114
ctid(0,114), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #116 is normal: length 56, offset 1592
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 115
ctid(0,115), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #117 is normal: length 56, offset 1536
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 116
ctid(0,116), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #118 is normal: length 56, offset 1480
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 117
ctid(0,117), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #119 is normal: length 56, offset 1424
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 118
ctid(0,118), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #120 is normal: length 56, offset 1368
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 119
ctid(0,119), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #121 is normal: length 56, offset 1312
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 120
ctid(0,120), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #122 is normal: length 56, offset 1256
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 121
ctid(0,121), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Summary (122 total): 0 unused, 122 normal, 0 dead, 0 redirect
UBTree index special information:
btree left sibling: 0
btree right sibling: 2
btree tree level: 0
btree flag: BTP_LEAF
btree cycle ID: 0
ubtree last_delete_xid: 0
ubtree xid_base: 0
ubtree active tuples: 121
The target page is from disk.
UBtree index page information of block 2/3
pd_lsn: 13/5E007440 ,len 8 ,offset 0
pd_checksum: 0x34CB, verify success, len 2, offset 8
pd_flags: 0x40
pd_lower: 76, non-empty, len 2, offset 12
pd_upper: 7416, old page, len 2, offset 14
pd_special: 8144, size 48, len 2, offset 16
Page size & version: 8192, 5, len 2, offset 18
pd_prune_xid: 0
Index tuple information on this page
Tuple #1 is normal: length 56, offset 8088
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 122
ctid(0,122), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #2 is normal: length 56, offset 8032
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 123
ctid(0,123), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #3 is normal: length 56, offset 7976
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 124
ctid(0,124), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #4 is normal: length 56, offset 7920
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 125
ctid(0,125), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #5 is normal: length 56, offset 7864
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 126
ctid(0,126), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs, has nulls
Tuple #6 is normal: length 56, offset 7808
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 127
ctid(0,127), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs, has nulls
Tuple #7 is normal: length 56, offset 7752
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 128
ctid(0,128), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #8 is normal: length 56, offset 7696
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 129
ctid(0,129), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #9 is normal: length 56, offset 7640
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 130
ctid(0,130), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #10 is normal: length 56, offset 7584
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 131
ctid(0,131), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #11 is normal: length 56, offset 7528
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 132
ctid(0,132), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #12 is normal: length 56, offset 7472
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 133
ctid(0,133), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs, has nulls
Tuple #13 is normal: length 56, offset 7416
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 134
ctid(0,134), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs, has nulls
Summary (13 total): 0 unused, 13 normal, 0 dead, 0 redirect
UBTree index special information:
btree left sibling: 1
btree right sibling: 0
btree tree level: 0
btree flag: BTP_LEAF
btree cycle ID: 0
ubtree last_delete_xid: 0
ubtree xid_base: 0
ubtree active tuples: 13
The target page is from disk.
UBtree index page information of block 3/3
pd_lsn: 13/5E007538 ,len 8 ,offset 0
pd_checksum: 0x8848, verify success, len 2, offset 8
pd_flags: 0x40
pd_lower: 32, non-empty, len 2, offset 12
pd_upper: 8112, old page, len 2, offset 14
pd_special: 8144, size 48, len 2, offset 16
Page size & version: 8192, 5, len 2, offset 18
pd_prune_xid: 0
Index tuple information on this page
Tuple #1 is normal: length 8, offset 8136
Heap Tid: block 0/1, offset 0
ctid(1,0), tablebucketid -1, tableoid 0
Length: 8
Tuple #2 is normal: length 24, offset 8112
Heap Tid: block 0/2, offset 3
ctid(2,3), tablebucketid -1, tableoid 0
Length: 24, has var-width attrs
Summary (2 total): 0 unused, 2 normal, 0 dead, 0 redirect
UBTree index special information:
btree left sibling: 0
btree right sibling: 0
btree tree level: 1
btree flag: BTP_INTERNAL BTP_ROOT
btree cycle ID: 0
ubtree last_delete_xid: 0
ubtree xid_base: 0
ubtree active tuples: 0
可以看到是3个块（从原索引文件里看到的第一个块叫元页面-Meta Page，不算），
这里显示第一个块 active tuples: 121,第二个块 active tuples: 13,第三个块 ubtree active tuples: 0 ,也就一共144行，和前面直接看二进制的结果差不多，数据都集中在两个块里，跳扫没找到的数据在13行的这个块里，也就是这两行
Tuple #1 is normal: length 56, offset 8088
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 122
ctid(0,122), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
Tuple #2 is normal: length 56, offset 8032
xmin:17625415 xmax:0 Heap Tid: block 0/0, offset 123
ctid(0,123), tablebucketid -1, tableoid 0
Length: 48, has var-width attrs
暂时只能分析到这里了，等华为排查给出原因后再更新。
20260203更新
华为答复：
- 【问题原因】
在索引包含多个字段且查询过滤条件包含索引列的后列，不包含前列，执行计划使用到索引跳过能力场景下，如果索引的前导组
(如:索引lindex(a,b,c),数据(0,1,a)(0,1,b),...,(0,1,n),(0,2,a)(0,2,b),...,(0,2,n),前导组即为数据(0,1)的所属行)中的数据跨越了多个页面，在扫描到第二个页面前，scankey(查询过滤条件组成的key)错误赋值，导致后续scankey与索引元组比较时，从而扫描行数和预期不符。- 【触发场景】
1、创建联合索引。
2、使用where条件进行select查询，且where条件中只包含索引列的后几列，不包含第一列，触发index skip scan的查询计划。- 【规避手段】打热补丁解决
- 【解决版本】506.0.0.HP0106
华为的这个答复和我猜想的原因是一样的，但也是没说为什么跨页的时候前导列会赋值错误，只是给了个这样的结果，那就看下这个补丁的文档里说了什么吧：
| 问题单号 | DTS2025121805690 |
|---|---|
| 问题描述 | IUDS+query并发压测索引扫描非法内存访问heap-use-after-free /usr1/GaussDBKernel/server/opengauss/src/auxiliary/share/adt/varlena_cmp.cpp:1195 in texteq(FunctionCallInfoData*) |
| 触发场景 | 1、创建联合索引。 2、使用where条件进行select查询，且where条件中只包含索引列的后几列，不包含第一列，触发index skip scan的查询计划。 3、并发DML。 |
| 严重级别 | 严重 |
| 根因分析 | 1、find_scankey_from_page根据前导列的分组tuple保存本次查询使用的scankey； 2、first根据1获取的scankey保存so->key_data，key_data的argument指向so->skip_old_tuple内存； 3、获取到tuple之后，又错误地调用了skip_save_tuple释放了so->skip_old_tuple的内存，但未更新so->key_data，key_data将会指向已释放的内存，后续出现内存问题。 |
| 解决方案 | 修改exec_skip_internal逻辑，find_scankey_from_page已经保存了本次分组的tuple和scankey，后续不需要再次保存。 |
| 补丁后操作 | 不涉及 |
| 修改影响 | 无影响 |
虽然本文问题的场景和这个补丁问题描述不一样，但从根因分析里可以看到，似乎是错误释放了内存，然后key_data指向了野地址。
索引跳扫的核心逻辑就是找到where条件里缺失的前导列的值，由于索引是有序的，它可以从索引里的第一个值开始拼（c1='0'），和SQL里的where条件组装在一起就可以走普通的索引范围扫描了，然后继续扫索引，当当前值和上一个值不一样时，就可以又组合出一组条件，依次直到索引的前导列扫完。但这里问题就发生在跨页的时候，GaussDB把上一个值的内存释放掉了，也就是值错了，但新页面前两行的前导列和上一个页面最后一行的前导列是一样的，本不需要再组装新条件的，它组装了新条件(c1=random)，就没找到这两行数据，然后继续往下，由于前导列值发生变化(c1='1')，所以又组装了正确的新条件，后面的数据都能扫到了。
但补丁里没说这个问题会导致数据查询结果错误，导致了客户在之前收到这个补丁的时候，误判了这个问题的严重性，没有及时进行补丁验证和更新。
我验证了下，打了这个补丁后，该用例的确已经恢复正常。
[Ruby@gaussdb-dn2 hotpatch]$ gs_om -t hotpatch -n $PWD/GaussDB-Kernel_506.0.0.SPC0100.HP0106.pat -c load
[SUCCESS] 192.168.163.119:
dn_6001
[2026-02-03 10:39:16.850][101974][][gs_ctl]: gs_ctl to control dcf cluster
[2026-02-03 10:39:16.912][101974][][gs_ctl]: [PATCH-SUCCESS] LOAD PATCH
dn_6002
[2026-02-03 10:39:16.920][102004][][gs_ctl]: gs_ctl to control dcf cluster
[2026-02-03 10:39:16.955][102004][][gs_ctl]: [PATCH-SUCCESS] LOAD PATCH
[SUCCESS] 192.168.163.118:
dn_6003
[2026-02-03 10:39:16.854][101077][][gs_ctl]: gs_ctl to control dcf cluster
[2026-02-03 10:39:16.901][101077][][gs_ctl]: [PATCH-SUCCESS] LOAD PATCH
############### S U M M A R Y ###############
SUCCESS: 3 FAILED 0
[SUCCESS] 192.168.163.119:
dn_6001
[2026-02-03 10:39:19.041][103482][][gs_ctl]: gs_ctl to control dcf cluster
[2026-02-03 10:39:19.090][103482][][gs_ctl]: [PATCH-SUCCESS] LOAD PATCH
dn_6002
[2026-02-03 10:39:19.101][103548][][gs_ctl]: gs_ctl to control dcf cluster
[2026-02-03 10:39:19.131][103548][][gs_ctl]: [PATCH-SUCCESS] LOAD PATCH
[SUCCESS] 192.168.163.118:
dn_6003
[2026-02-03 10:39:19.381][101766][][gs_ctl]: gs_ctl to control dcf cluster
[2026-02-03 10:39:19.407][101766][][gs_ctl]: [PATCH-SUCCESS] LOAD PATCH
############### S U M M A R Y ###############
SUCCESS: 3 FAILED 0
[SUCCESS] 192.168.163.119:
OM:
[PATCH-SUCCESS] LOAD PATCH
[SUCCESS] 192.168.163.118:
OM:
[PATCH-SUCCESS] LOAD PATCH
############### S U M M A R Y ###############
SUCCESS: 2 FAILED 0
[Ruby@gaussdb-dn2 hotpatch]$ gs_om -t hotpatch -n KERNEL -c list
[SUCCESS] 192.168.163.119:
dn_6001
[2026-02-03 10:39:38.030][113128][][gs_ctl]: gs_ctl to control dcf cluster
PATCH: GaussDB-Kernel_KERNELHP_506.0.0.SPC0100.0105.pat STATE: ACTIVE
PATCH: GaussDB-Kernel_KERNELHP_506.0.0.SPC0100.0106.pat STATE: DEACTIVE
PATCH: GaussDB-Kernel_KERNELHP_EXTENSION_platform_compatibility_b_506.0.0.SPC0100.0106.pat STATE: DEACTIVE
[PATCH-SUCCESS] LIST PATCH
dn_6002
[2026-02-03 10:39:38.091][113149][][gs_ctl]: gs_ctl to control dcf cluster
PATCH: GaussDB-Kernel_KERNELHP_506.0.0.SPC0100.0105.pat STATE: ACTIVE
PATCH: GaussDB-Kernel_KERNELHP_506.0.0.SPC0100.0106.pat STATE: DEACTIVE
PATCH: GaussDB-Kernel_KERNELHP_EXTENSION_platform_compatibility_b_506.0.0.SPC0100.0106.pat STATE: DEACTIVE
[PATCH-SUCCESS] LIST PATCH
[SUCCESS] 192.168.163.118:
dn_6003
[2026-02-03 10:39:38.027][111546][][gs_ctl]: gs_ctl to control dcf cluster
PATCH: GaussDB-Kernel_KERNELHP_506.0.0.SPC0100.0105.pat STATE: ACTIVE
PATCH: GaussDB-Kernel_KERNELHP_506.0.0.SPC0100.0106.pat STATE: DEACTIVE
PATCH: GaussDB-Kernel_KERNELHP_EXTENSION_platform_compatibility_b_506.0.0.SPC0100.0106.pat STATE: DEACTIVE
[PATCH-SUCCESS] LIST PATCH
############### S U M M A R Y ###############
PATCH: GaussDB-Kernel_KERNELHP_506.0.0.SPC0100.0105.pat ACTIVE 3 DEACTIVE 0
PATCH: GaussDB-Kernel_KERNELHP_506.0.0.SPC0100.0106.pat ACTIVE 0 DEACTIVE 3
PATCH: GaussDB-Kernel_KERNELHP_EXTENSION_platform_compatibility_b_506.0.0.SPC0100.0106.pat ACTIVE 0 DEACTIVE 3
SUCCESS: 3 FAILED 0
[Ruby@gaussdb-dn2 hotpatch]$ gs_om -t hotpatch -n GaussDB-Kernel_KERNELHP_506.0.0.SPC0100.0106.pat -c active
[SUCCESS] 192.168.163.119:
dn_6001
[2026-02-03 10:40:18.959][129085][][gs_ctl]: gs_ctl to control dcf cluster
[2026-02-03 10:40:18.994][129085][][gs_ctl]: [PATCH-SUCCESS] ACTIVE PATCH
dn_6002
[2026-02-03 10:40:19.005][129103][][gs_ctl]: gs_ctl to control dcf cluster
[2026-02-03 10:40:19.036][129103][][gs_ctl]: [PATCH-SUCCESS] ACTIVE PATCH
[SUCCESS] 192.168.163.118:
dn_6003
[2026-02-03 10:40:18.970][126776][][gs_ctl]: gs_ctl to control dcf cluster
[2026-02-03 10:40:19.000][126776][][gs_ctl]: [PATCH-SUCCESS] ACTIVE PATCH
############### S U M M A R Y ###############
SUCCESS: 3 FAILED 0
[Ruby@gaussdb-dn2 hotpatch]$
[Ruby@gaussdb-dn2 hotpatch]$ gsql -r -d postgres -p 8000
gsql ((GaussDB Kernel 506.0.0.SPC0100 build e324981f) compiled at 2025-04-27 14:27:52 last mr 23420 release)
Non-SSL connection (SSL connection is recommended when requiring high-security)
Type "help" for help.
gaussdb=# set search_path=root;
SET
gaussdb=# select /*+IndexSkipScan(t ind_t_test_skip)*/ count(1) from t_test_skip t where c2 in ('6','7')
gaussdb-# union all
gaussdb-# select /*+tablescan(t)*/ count(1) from t_test_skip t where c2 in ('6','7');
count
-------
127
127
(2 rows)
gaussdb=#
