Re: 13dev failed assert: comparetup_index_btree(): ItemPointer values should never be equal

> Justin Pryzby <pryzby(at)telsasoft(dot)com> writes:
> > I have nothing new to add, but wanted to point out this is still an issue.
> > This is on the v13 Opened Items list - for lack of anywhere else to put them, I
> > also added two other, unresolved issues.

Two minor things to add:
1. This issue is still reproducible on 15Beta2 (c1d033fcb5) - Backtrace here [2]
2. There was a mention that amcheck could throw up errors, but despite quickly
stopping the workload, I didn't find anything interesting [1].

(gdb) frame 3
#3 0x000055bf9fe496c8 in comparetup_index_btree (a=0x7f0a1a50ba80,
b=0x7f0a1a50b9d8, state=0x55bfa19ce960) at tuplesort.c:4454
4454 Assert(false);

(gdb) info locals
sortKey = 0x55bfa19cef10
tuple1 = 0x7f0a1a563ee0
tuple2 = 0x7f0a1a5642a0
keysz = 2
tupDes = 0x7f0a1a9e66a8
equal_hasnull = false
nkey = 3
compare = 0
datum1 = 2085305
datum2 = 2085305
isnull1 = false
isnull2 = false
__func__ = "comparetup_index_btree"

(gdb) p *tuple1
$5 = {t_tid = {ip_blkid = {bi_hi = 0, bi_lo = 205}, ip_posid = 3}, t_info = 16}

(gdb) p *tuple2
$9 = {t_tid = {ip_blkid = {bi_hi = 0, bi_lo = 205}, ip_posid = 3}, t_info = 16}

(gdb) p *sortKey
$7 = {ssup_cxt = 0x40, ssup_collation = 0, ssup_reverse = false,
ssup_nulls_first = false, ssup_attno = 0, ssup_extra = 0x0, comparator
= 0x7f7f7f7f7f7f7f7f, abbreviate = 127,
abbrev_converter = 0x7f7f7f7f7f7f7f7f, abbrev_abort =
0x7f7f7f7f7f7f7f7f, abbrev_full_comparator = 0x7f7f7f7f7f7f7f7f}

(gdb) p *tupDes
$8 = {natts = 2, tdtypeid = 2249, tdtypmod = -1, tdrefcount = 1,
constr = 0x0, attrs = 0x7f0a1a9e66c0}

Reference:
1) postgres=# select
bt_index_parent_check('pg_class_tblspc_relfilenode_index', true,
true);
bt_index_parent_check
-----------------------

(1 row)

postgres=# select bt_index_check('pg_class_tblspc_relfilenode_index', true);
bt_index_check
----------------

(1 row)

2) Backtrace -
(gdb) bt
#0 __GI_raise (sig=sig(at)entry=6) at ../sysdeps/unix/sysv/linux/raise.c:50
#1 0x00007f0a25692859 in __GI_abort () at abort.c:79
#2 0x000055bf9fdf1718 in ExceptionalCondition
(conditionName=0x55bfa0036a0b "false", errorType=0x55bfa0035d5e
"FailedAssertion", fileName=0x55bfa0035dbd "tuplesort.c",
lineNumber=4454)
at assert.c:69
#3 0x000055bf9fe496c8 in comparetup_index_btree (a=0x7f0a1a50ba80,
b=0x7f0a1a50b9d8, state=0x55bfa19ce960) at tuplesort.c:4454
#4 0x000055bf9fe40901 in qsort_tuple (data=0x7f0a1a50b8e8, n=13,
compare=0x55bf9fe484ab <comparetup_index_btree>, arg=0x55bfa19ce960)
at ../../../../src/include/lib/sort_template.h:341
#5 0x000055bf9fe40b2f in qsort_tuple (data=0x7f0a1a50b3a8, n=61,
compare=0x55bf9fe484ab <comparetup_index_btree>, arg=0x55bfa19ce960)
at ../../../../src/include/lib/sort_template.h:378
#6 0x000055bf9fe40b9f in qsort_tuple (data=0x7f0a1a509e78, n=343,
compare=0x55bf9fe484ab <comparetup_index_btree>, arg=0x55bfa19ce960)
at ../../../../src/include/lib/sort_template.h:392
#7 0x000055bf9fe40b2f in qsort_tuple (data=0x7f0a1a509e78, n=833,
compare=0x55bf9fe484ab <comparetup_index_btree>, arg=0x55bfa19ce960)
at ../../../../src/include/lib/sort_template.h:378
#8 0x000055bf9fe40b9f in qsort_tuple (data=0x7f0a1a4d9050, n=2118,
compare=0x55bf9fe484ab <comparetup_index_btree>, arg=0x55bfa19ce960)
at ../../../../src/include/lib/sort_template.h:392
#9 0x000055bf9fe46df8 in tuplesort_sort_memtuples
(state=0x55bfa19ce960) at tuplesort.c:3698
#10 0x000055bf9fe44043 in tuplesort_performsort (state=0x55bfa19ce960)
at tuplesort.c:2217
#11 0x000055bf9f783a85 in _bt_leafbuild (btspool=0x55bfa1913318,
btspool2=0x0) at nbtsort.c:559
#12 0x000055bf9f7835a6 in btbuild (heap=0x7f0a1a9df940,
index=0x7f0a1a9e2898, indexInfo=0x55bfa19bc740) at nbtsort.c:336
#13 0x000055bf9f81c8cc in index_build (heapRelation=0x7f0a1a9df940,
indexRelation=0x7f0a1a9e2898, indexInfo=0x55bfa19bc740,
isreindex=true, parallel=true) at index.c:3018
#14 0x000055bf9f81dbe6 in reindex_index (indexId=3455,
skip_constraint_checks=false, persistence=112 'p',
params=0x7ffcfa60a524) at index.c:3718
#15 0x000055bf9f925148 in ReindexIndex (indexRelation=0x55bfa18f09a0,
params=0x7ffcfa60a598, isTopLevel=true) at indexcmds.c:2727
#16 0x000055bf9f924f67 in ExecReindex (pstate=0x55bfa1913070,
stmt=0x55bfa18f09f8, isTopLevel=true) at indexcmds.c:2651
#17 0x000055bf9fc3397f in standard_ProcessUtility
(pstmt=0x55bfa18f0d48, queryString=0x55bfa18eff30 "REINDEX INDEX
pg_class_tblspc_relfilenode_index;", readOnlyTree=false,
context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0,
dest=0x55bfa18f0e38, qc=0x7ffcfa60ad20) at utility.c:960
#18 0x00007f0a251d6887 in pgss_ProcessUtility (pstmt=0x55bfa18f0d48,
queryString=0x55bfa18eff30 "REINDEX INDEX
pg_class_tblspc_relfilenode_index;", readOnlyTree=false,
context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0,
dest=0x55bfa18f0e38, qc=0x7ffcfa60ad20) at pg_stat_statements.c:1143
#19 0x000055bf9fc32d34 in ProcessUtility (pstmt=0x55bfa18f0d48,
queryString=0x55bfa18eff30 "REINDEX INDEX
pg_class_tblspc_relfilenode_index;", readOnlyTree=false,
context=PROCESS_UTILITY_TOPLEVEL, params=0x0, queryEnv=0x0,
dest=0x55bfa18f0e38, qc=0x7ffcfa60ad20) at utility.c:526
#20 0x000055bf9fc3180e in PortalRunUtility (portal=0x55bfa197d020,
pstmt=0x55bfa18f0d48, isTopLevel=true, setHoldSnapshot=false,
dest=0x55bfa18f0e38, qc=0x7ffcfa60ad20) at pquery.c:1158
#21 0x000055bf9fc31a84 in PortalRunMulti (portal=0x55bfa197d020,
isTopLevel=true, setHoldSnapshot=false, dest=0x55bfa18f0e38,
altdest=0x55bfa18f0e38, qc=0x7ffcfa60ad20) at pquery.c:1315
#22 0x000055bf9fc30ef1 in PortalRun (portal=0x55bfa197d020,
count=9223372036854775807, isTopLevel=true, run_once=true,
dest=0x55bfa18f0e38, altdest=0x55bfa18f0e38, qc=0x7ffcfa60ad20)
at pquery.c:791
#23 0x000055bf9fc2a14f in exec_simple_query
(query_string=0x55bfa18eff30 "REINDEX INDEX
pg_class_tblspc_relfilenode_index;") at postgres.c:1250
#24 0x000055bf9fc2ecdf in PostgresMain (dbname=0x55bfa1923be0
"postgres", username=0x55bfa18eb8f8 "ubuntu") at postgres.c:4544
#25 0x000055bf9fb52e93 in BackendRun (port=0x55bfa19218a0) at postmaster.c:4504
#26 0x000055bf9fb52778 in BackendStartup (port=0x55bfa19218a0) at
postmaster.c:4232
#27 0x000055bf9fb4ea5e in ServerLoop () at postmaster.c:1806
#28 0x000055bf9fb4e1f7 in PostmasterMain (argc=3, argv=0x55bfa18e9830)
at postmaster.c:1478
#29 0x000055bf9fa3f864 in main (argc=3, argv=0x55bfa18e9830) at main.c:202

-
Robins Tharakan
Amazon Web Services